tuned white space;
authorwenzelm
Fri, 16 Oct 2009 10:55:07 +0200
changeset 32956 c39860141415
parent 32955 4a78daeb012b
child 32957 675c0c7e6a37
child 32962 4772d8dd18f8
child 33053 dabf9d1bb552
tuned white space;
src/HOL/Tools/metis_tools.ML
--- a/src/HOL/Tools/metis_tools.ML	Fri Oct 16 10:45:10 2009 +0200
+++ b/src/HOL/Tools/metis_tools.ML	Fri Oct 16 10:55:07 2009 +0200
@@ -18,728 +18,728 @@
 structure MetisTools: METIS_TOOLS =
 struct
 
-  val trace = Unsynchronized.ref false;
-  fun trace_msg msg = if ! trace then tracing (msg ()) else ();
+val trace = Unsynchronized.ref false;
+fun trace_msg msg = if ! trace then tracing (msg ()) else ();
 
-  structure Recon = ResReconstruct;
+structure Recon = ResReconstruct;
 
-  val (type_lits, type_lits_setup) = Attrib.config_bool "metis_type_lits" true;
+val (type_lits, type_lits_setup) = Attrib.config_bool "metis_type_lits" true;
 
-  datatype mode = FO | HO | FT  (*first-order, higher-order, fully-typed*)
+datatype mode = FO | HO | FT  (*first-order, higher-order, fully-typed*)
 
-  (* ------------------------------------------------------------------------- *)
-  (* Useful Theorems                                                           *)
-  (* ------------------------------------------------------------------------- *)
-  val EXCLUDED_MIDDLE = rotate_prems 1 (read_instantiate @{context} [(("R", 0), "False")] notE);
-  val REFL_THM = incr_indexes 2 (Meson.make_meta_clause refl);  (*Rename from 0,1*)
-  val subst_em  = zero_var_indexes (subst RS EXCLUDED_MIDDLE);
-  val ssubst_em = read_instantiate @{context} [(("t", 0), "?s"), (("s", 0), "?t")] (sym RS subst_em);
+(* ------------------------------------------------------------------------- *)
+(* Useful Theorems                                                           *)
+(* ------------------------------------------------------------------------- *)
+val EXCLUDED_MIDDLE = rotate_prems 1 (read_instantiate @{context} [(("R", 0), "False")] notE);
+val REFL_THM = incr_indexes 2 (Meson.make_meta_clause refl);  (*Rename from 0,1*)
+val subst_em  = zero_var_indexes (subst RS EXCLUDED_MIDDLE);
+val ssubst_em = read_instantiate @{context} [(("t", 0), "?s"), (("s", 0), "?t")] (sym RS subst_em);
 
-  (* ------------------------------------------------------------------------- *)
-  (* Useful Functions                                                          *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* Useful Functions                                                          *)
+(* ------------------------------------------------------------------------- *)
 
-  (* match untyped terms*)
-  fun untyped_aconv (Const(a,_))   (Const(b,_))   = (a=b)
-    | untyped_aconv (Free(a,_))    (Free(b,_))    = (a=b)
-    | untyped_aconv (Var((a,_),_)) (Var((b,_),_)) = (a=b)   (*the index is ignored!*)
-    | untyped_aconv (Bound i)      (Bound j)      = (i=j)
-    | untyped_aconv (Abs(a,_,t))  (Abs(b,_,u))    = (a=b) andalso untyped_aconv t u
-    | untyped_aconv (t1$t2) (u1$u2)  = untyped_aconv t1 u1 andalso untyped_aconv t2 u2
-    | untyped_aconv _              _              = false;
+(* match untyped terms*)
+fun untyped_aconv (Const(a,_))   (Const(b,_))   = (a=b)
+  | untyped_aconv (Free(a,_))    (Free(b,_))    = (a=b)
+  | untyped_aconv (Var((a,_),_)) (Var((b,_),_)) = (a=b)   (*the index is ignored!*)
+  | untyped_aconv (Bound i)      (Bound j)      = (i=j)
+  | untyped_aconv (Abs(a,_,t))  (Abs(b,_,u))    = (a=b) andalso untyped_aconv t u
+  | untyped_aconv (t1$t2) (u1$u2)  = untyped_aconv t1 u1 andalso untyped_aconv t2 u2
+  | untyped_aconv _              _              = false;
 
-  (* Finding the relative location of an untyped term within a list of terms *)
-  fun get_index lit =
-    let val lit = Envir.eta_contract lit
-        fun get n [] = raise Empty
-          | get n (x::xs) = if untyped_aconv lit (Envir.eta_contract (HOLogic.dest_Trueprop x))
-                            then n  else get (n+1) xs
-    in get 1 end;
+(* Finding the relative location of an untyped term within a list of terms *)
+fun get_index lit =
+  let val lit = Envir.eta_contract lit
+      fun get n [] = raise Empty
+        | get n (x::xs) = if untyped_aconv lit (Envir.eta_contract (HOLogic.dest_Trueprop x))
+                          then n  else get (n+1) xs
+  in get 1 end;
 
-  (* ------------------------------------------------------------------------- *)
-  (* HOL to FOL  (Isabelle to Metis)                                           *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* HOL to FOL  (Isabelle to Metis)                                           *)
+(* ------------------------------------------------------------------------- *)
 
-  fun fn_isa_to_met "equal" = "="
-    | fn_isa_to_met x       = x;
+fun fn_isa_to_met "equal" = "="
+  | fn_isa_to_met x       = x;
 
-  fun metis_lit b c args = (b, (c, args));
+fun metis_lit b c args = (b, (c, args));
 
-  fun hol_type_to_fol (ResClause.AtomV x) = Metis.Term.Var x
-    | hol_type_to_fol (ResClause.AtomF x) = Metis.Term.Fn(x,[])
-    | hol_type_to_fol (ResClause.Comp(tc,tps)) = Metis.Term.Fn(tc, map hol_type_to_fol tps);
+fun hol_type_to_fol (ResClause.AtomV x) = Metis.Term.Var x
+  | hol_type_to_fol (ResClause.AtomF x) = Metis.Term.Fn(x,[])
+  | hol_type_to_fol (ResClause.Comp(tc,tps)) = Metis.Term.Fn(tc, map hol_type_to_fol tps);
 
-  (*These two functions insert type literals before the real literals. That is the
-    opposite order from TPTP linkup, but maybe OK.*)
+(*These two functions insert type literals before the real literals. That is the
+  opposite order from TPTP linkup, but maybe OK.*)
 
-  fun hol_term_to_fol_FO tm =
-    case ResHolClause.strip_comb tm of
-        (ResHolClause.CombConst(c,_,tys), tms) =>
-          let val tyargs = map hol_type_to_fol tys
-              val args   = map hol_term_to_fol_FO tms
-          in Metis.Term.Fn (c, tyargs @ args) end
-      | (ResHolClause.CombVar(v,_), []) => Metis.Term.Var v
-      | _ => error "hol_term_to_fol_FO";
+fun hol_term_to_fol_FO tm =
+  case ResHolClause.strip_comb tm of
+      (ResHolClause.CombConst(c,_,tys), tms) =>
+        let val tyargs = map hol_type_to_fol tys
+            val args   = map hol_term_to_fol_FO tms
+        in Metis.Term.Fn (c, tyargs @ args) end
+    | (ResHolClause.CombVar(v,_), []) => Metis.Term.Var v
+    | _ => error "hol_term_to_fol_FO";
 
-  fun hol_term_to_fol_HO (ResHolClause.CombVar(a, ty)) = Metis.Term.Var a
-    | hol_term_to_fol_HO (ResHolClause.CombConst(a, ty, tylist)) =
-        Metis.Term.Fn(fn_isa_to_met a, map hol_type_to_fol tylist)
-    | hol_term_to_fol_HO (ResHolClause.CombApp(tm1,tm2)) =
-         Metis.Term.Fn(".", map hol_term_to_fol_HO [tm1,tm2]);
+fun hol_term_to_fol_HO (ResHolClause.CombVar(a, ty)) = Metis.Term.Var a
+  | hol_term_to_fol_HO (ResHolClause.CombConst(a, ty, tylist)) =
+      Metis.Term.Fn(fn_isa_to_met a, map hol_type_to_fol tylist)
+  | hol_term_to_fol_HO (ResHolClause.CombApp(tm1,tm2)) =
+       Metis.Term.Fn(".", map hol_term_to_fol_HO [tm1,tm2]);
 
-  (*The fully-typed translation, to avoid type errors*)
-  fun wrap_type (tm, ty) = Metis.Term.Fn("ti", [tm, hol_type_to_fol ty]);
-  
-  fun hol_term_to_fol_FT (ResHolClause.CombVar(a, ty)) = 
-        wrap_type (Metis.Term.Var a, ty)
-    | hol_term_to_fol_FT (ResHolClause.CombConst(a, ty, _)) =
-        wrap_type (Metis.Term.Fn(fn_isa_to_met a, []), ty)
-    | hol_term_to_fol_FT (tm as ResHolClause.CombApp(tm1,tm2)) =
-         wrap_type (Metis.Term.Fn(".", map hol_term_to_fol_FT [tm1,tm2]),    
-                    ResHolClause.type_of_combterm tm);
+(*The fully-typed translation, to avoid type errors*)
+fun wrap_type (tm, ty) = Metis.Term.Fn("ti", [tm, hol_type_to_fol ty]);
+
+fun hol_term_to_fol_FT (ResHolClause.CombVar(a, ty)) =
+      wrap_type (Metis.Term.Var a, ty)
+  | hol_term_to_fol_FT (ResHolClause.CombConst(a, ty, _)) =
+      wrap_type (Metis.Term.Fn(fn_isa_to_met a, []), ty)
+  | hol_term_to_fol_FT (tm as ResHolClause.CombApp(tm1,tm2)) =
+       wrap_type (Metis.Term.Fn(".", map hol_term_to_fol_FT [tm1,tm2]),
+                  ResHolClause.type_of_combterm tm);
 
-  fun hol_literal_to_fol FO (ResHolClause.Literal (pol, tm)) =  
-        let val (ResHolClause.CombConst(p,_,tys), tms) = ResHolClause.strip_comb tm
-            val tylits = if p = "equal" then [] else map hol_type_to_fol tys
-            val lits = map hol_term_to_fol_FO tms
-        in metis_lit pol (fn_isa_to_met p) (tylits @ lits) end
-    | hol_literal_to_fol HO (ResHolClause.Literal (pol, tm)) =
-       (case ResHolClause.strip_comb tm of
-            (ResHolClause.CombConst("equal",_,_), tms) =>
-              metis_lit pol "=" (map hol_term_to_fol_HO tms)
-          | _ => metis_lit pol "{}" [hol_term_to_fol_HO tm])   (*hBOOL*)
-    | hol_literal_to_fol FT (ResHolClause.Literal (pol, tm)) = 
-       (case ResHolClause.strip_comb tm of
-            (ResHolClause.CombConst("equal",_,_), tms) =>
-              metis_lit pol "=" (map hol_term_to_fol_FT tms)
-          | _ => metis_lit pol "{}" [hol_term_to_fol_FT tm])   (*hBOOL*);
+fun hol_literal_to_fol FO (ResHolClause.Literal (pol, tm)) =
+      let val (ResHolClause.CombConst(p,_,tys), tms) = ResHolClause.strip_comb tm
+          val tylits = if p = "equal" then [] else map hol_type_to_fol tys
+          val lits = map hol_term_to_fol_FO tms
+      in metis_lit pol (fn_isa_to_met p) (tylits @ lits) end
+  | hol_literal_to_fol HO (ResHolClause.Literal (pol, tm)) =
+     (case ResHolClause.strip_comb tm of
+          (ResHolClause.CombConst("equal",_,_), tms) =>
+            metis_lit pol "=" (map hol_term_to_fol_HO tms)
+        | _ => metis_lit pol "{}" [hol_term_to_fol_HO tm])   (*hBOOL*)
+  | hol_literal_to_fol FT (ResHolClause.Literal (pol, tm)) =
+     (case ResHolClause.strip_comb tm of
+          (ResHolClause.CombConst("equal",_,_), tms) =>
+            metis_lit pol "=" (map hol_term_to_fol_FT tms)
+        | _ => metis_lit pol "{}" [hol_term_to_fol_FT tm])   (*hBOOL*);
 
-  fun literals_of_hol_thm thy mode t =
-        let val (lits, types_sorts) = ResHolClause.literals_of_term thy t
-        in  (map (hol_literal_to_fol mode) lits, types_sorts) end;
+fun literals_of_hol_thm thy mode t =
+      let val (lits, types_sorts) = ResHolClause.literals_of_term thy t
+      in  (map (hol_literal_to_fol mode) lits, types_sorts) end;
 
-  (*Sign should be "true" for conjecture type constraints, "false" for type lits in clauses.*)
-  fun metis_of_typeLit pos (ResClause.LTVar (s,x))  = metis_lit pos s [Metis.Term.Var x]
-    | metis_of_typeLit pos (ResClause.LTFree (s,x)) = metis_lit pos s [Metis.Term.Fn(x,[])];
+(*Sign should be "true" for conjecture type constraints, "false" for type lits in clauses.*)
+fun metis_of_typeLit pos (ResClause.LTVar (s,x))  = metis_lit pos s [Metis.Term.Var x]
+  | metis_of_typeLit pos (ResClause.LTFree (s,x)) = metis_lit pos s [Metis.Term.Fn(x,[])];
 
-  fun default_sort ctxt (TVar _) = false
-    | default_sort ctxt (TFree(x,s)) = (s = Option.getOpt (Variable.def_sort ctxt (x,~1), []));
+fun default_sort ctxt (TVar _) = false
+  | default_sort ctxt (TFree(x,s)) = (s = Option.getOpt (Variable.def_sort ctxt (x,~1), []));
 
-  fun metis_of_tfree tf =
-    Metis.Thm.axiom (Metis.LiteralSet.singleton (metis_of_typeLit true tf));
+fun metis_of_tfree tf =
+  Metis.Thm.axiom (Metis.LiteralSet.singleton (metis_of_typeLit true tf));
 
-  fun hol_thm_to_fol is_conjecture ctxt mode th =
-    let val thy = ProofContext.theory_of ctxt
-        val (mlits, types_sorts) =
-               (literals_of_hol_thm thy mode o HOLogic.dest_Trueprop o prop_of) th
-    in
-        if is_conjecture then
-            (Metis.Thm.axiom (Metis.LiteralSet.fromList mlits), ResClause.add_typs types_sorts)
-        else
-          let val tylits = ResClause.add_typs
-                             (filter (not o default_sort ctxt) types_sorts)
-              val mtylits = if Config.get ctxt type_lits
-                            then map (metis_of_typeLit false) tylits else []
-          in
-            (Metis.Thm.axiom (Metis.LiteralSet.fromList(mtylits @ mlits)), [])
-          end
-    end;
+fun hol_thm_to_fol is_conjecture ctxt mode th =
+  let val thy = ProofContext.theory_of ctxt
+      val (mlits, types_sorts) =
+             (literals_of_hol_thm thy mode o HOLogic.dest_Trueprop o prop_of) th
+  in
+      if is_conjecture then
+          (Metis.Thm.axiom (Metis.LiteralSet.fromList mlits), ResClause.add_typs types_sorts)
+      else
+        let val tylits = ResClause.add_typs
+                           (filter (not o default_sort ctxt) types_sorts)
+            val mtylits = if Config.get ctxt type_lits
+                          then map (metis_of_typeLit false) tylits else []
+        in
+          (Metis.Thm.axiom (Metis.LiteralSet.fromList(mtylits @ mlits)), [])
+        end
+  end;
 
-  (* ARITY CLAUSE *)
+(* ARITY CLAUSE *)
 
-  fun m_arity_cls (ResClause.TConsLit (c,t,args)) =
-        metis_lit true (ResClause.make_type_class c) [Metis.Term.Fn(t, map Metis.Term.Var args)]
-    | m_arity_cls (ResClause.TVarLit (c,str))     =
-        metis_lit false (ResClause.make_type_class c) [Metis.Term.Var str];
+fun m_arity_cls (ResClause.TConsLit (c,t,args)) =
+      metis_lit true (ResClause.make_type_class c) [Metis.Term.Fn(t, map Metis.Term.Var args)]
+  | m_arity_cls (ResClause.TVarLit (c,str))     =
+      metis_lit false (ResClause.make_type_class c) [Metis.Term.Var str];
 
-  (*TrueI is returned as the Isabelle counterpart because there isn't any.*)
-  fun arity_cls (ResClause.ArityClause{conclLit,premLits,...}) =
-    (TrueI,
-     Metis.Thm.axiom (Metis.LiteralSet.fromList (map m_arity_cls (conclLit :: premLits))));
+(*TrueI is returned as the Isabelle counterpart because there isn't any.*)
+fun arity_cls (ResClause.ArityClause{conclLit,premLits,...}) =
+  (TrueI,
+   Metis.Thm.axiom (Metis.LiteralSet.fromList (map m_arity_cls (conclLit :: premLits))));
 
-  (* CLASSREL CLAUSE *)
+(* CLASSREL CLAUSE *)
 
-  fun m_classrel_cls subclass superclass =
-    [metis_lit false subclass [Metis.Term.Var "T"], metis_lit true superclass [Metis.Term.Var "T"]];
+fun m_classrel_cls subclass superclass =
+  [metis_lit false subclass [Metis.Term.Var "T"], metis_lit true superclass [Metis.Term.Var "T"]];
 
-  fun classrel_cls (ResClause.ClassrelClause {axiom_name,subclass,superclass,...}) =
-    (TrueI, Metis.Thm.axiom (Metis.LiteralSet.fromList (m_classrel_cls subclass superclass)));
+fun classrel_cls (ResClause.ClassrelClause {axiom_name,subclass,superclass,...}) =
+  (TrueI, Metis.Thm.axiom (Metis.LiteralSet.fromList (m_classrel_cls subclass superclass)));
 
-  (* ------------------------------------------------------------------------- *)
-  (* FOL to HOL  (Metis to Isabelle)                                           *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* FOL to HOL  (Metis to Isabelle)                                           *)
+(* ------------------------------------------------------------------------- *)
 
- datatype term_or_type = Term of Term.term | Type of Term.typ;
+datatype term_or_type = Term of Term.term | Type of Term.typ;
 
-  fun terms_of [] = []
-    | terms_of (Term t :: tts) = t :: terms_of tts
-    | terms_of (Type _ :: tts) = terms_of tts;
+fun terms_of [] = []
+  | terms_of (Term t :: tts) = t :: terms_of tts
+  | terms_of (Type _ :: tts) = terms_of tts;
 
-  fun types_of [] = []
-    | types_of (Term (Term.Var((a,idx), T)) :: tts) =
-        if String.isPrefix "_" a then
-            (*Variable generated by Metis, which might have been a type variable.*)
-            TVar(("'" ^ a, idx), HOLogic.typeS) :: types_of tts
-        else types_of tts
-    | types_of (Term _ :: tts) = types_of tts
-    | types_of (Type T :: tts) = T :: types_of tts;
+fun types_of [] = []
+  | types_of (Term (Term.Var((a,idx), T)) :: tts) =
+      if String.isPrefix "_" a then
+          (*Variable generated by Metis, which might have been a type variable.*)
+          TVar(("'" ^ a, idx), HOLogic.typeS) :: types_of tts
+      else types_of tts
+  | types_of (Term _ :: tts) = types_of tts
+  | types_of (Type T :: tts) = T :: types_of tts;
 
-  fun apply_list rator nargs rands =
-    let val trands = terms_of rands
-    in  if length trands = nargs then Term (list_comb(rator, trands))
-        else error
-          ("apply_list: wrong number of arguments: " ^ Syntax.string_of_term_global Pure.thy rator ^
-            " expected " ^ Int.toString nargs ^
-            " received " ^ commas (map (Syntax.string_of_term_global Pure.thy) trands))
-    end;
+fun apply_list rator nargs rands =
+  let val trands = terms_of rands
+  in  if length trands = nargs then Term (list_comb(rator, trands))
+      else error
+        ("apply_list: wrong number of arguments: " ^ Syntax.string_of_term_global Pure.thy rator ^
+          " expected " ^ Int.toString nargs ^
+          " received " ^ commas (map (Syntax.string_of_term_global Pure.thy) trands))
+  end;
 
 fun infer_types ctxt =
   Syntax.check_terms (ProofContext.set_mode ProofContext.mode_pattern ctxt);
 
-  (*We use 1 rather than 0 because variable references in clauses may otherwise conflict
-    with variable constraints in the goal...at least, type inference often fails otherwise.
-    SEE ALSO axiom_inf below.*)
-  fun mk_var (w,T) = Term.Var((w,1), T);
+(*We use 1 rather than 0 because variable references in clauses may otherwise conflict
+  with variable constraints in the goal...at least, type inference often fails otherwise.
+  SEE ALSO axiom_inf below.*)
+fun mk_var (w,T) = Term.Var((w,1), T);
 
-  (*include the default sort, if available*)
-  fun mk_tfree ctxt w =
-    let val ww = "'" ^ w
-    in  TFree(ww, getOpt (Variable.def_sort ctxt (ww,~1), HOLogic.typeS))  end;
+(*include the default sort, if available*)
+fun mk_tfree ctxt w =
+  let val ww = "'" ^ w
+  in  TFree(ww, getOpt (Variable.def_sort ctxt (ww,~1), HOLogic.typeS))  end;
 
-  (*Remove the "apply" operator from an HO term*)
-  fun strip_happ args (Metis.Term.Fn(".",[t,u])) = strip_happ (u::args) t
-    | strip_happ args x = (x, args);
+(*Remove the "apply" operator from an HO term*)
+fun strip_happ args (Metis.Term.Fn(".",[t,u])) = strip_happ (u::args) t
+  | strip_happ args x = (x, args);
 
-  fun fol_type_to_isa ctxt (Metis.Term.Var v) = 
-       (case Recon.strip_prefix ResClause.tvar_prefix v of
-	    SOME w => Recon.make_tvar w
-	  | NONE   => Recon.make_tvar v)
-    | fol_type_to_isa ctxt (Metis.Term.Fn(x, tys)) =
-       (case Recon.strip_prefix ResClause.tconst_prefix x of
-	    SOME tc => Term.Type (Recon.invert_type_const tc, map (fol_type_to_isa ctxt) tys)
-	  | NONE    => 
-        case Recon.strip_prefix ResClause.tfree_prefix x of
-	    SOME tf => mk_tfree ctxt tf
-	  | NONE    => error ("fol_type_to_isa: " ^ x));
+fun fol_type_to_isa ctxt (Metis.Term.Var v) =
+     (case Recon.strip_prefix ResClause.tvar_prefix v of
+          SOME w => Recon.make_tvar w
+        | NONE   => Recon.make_tvar v)
+  | fol_type_to_isa ctxt (Metis.Term.Fn(x, tys)) =
+     (case Recon.strip_prefix ResClause.tconst_prefix x of
+          SOME tc => Term.Type (Recon.invert_type_const tc, map (fol_type_to_isa ctxt) tys)
+        | NONE    =>
+      case Recon.strip_prefix ResClause.tfree_prefix x of
+          SOME tf => mk_tfree ctxt tf
+        | NONE    => error ("fol_type_to_isa: " ^ x));
 
-  (*Maps metis terms to isabelle terms*)
-  fun fol_term_to_hol_RAW ctxt fol_tm =
-    let val thy = ProofContext.theory_of ctxt
-        val _ = trace_msg (fn () => "fol_term_to_hol: " ^ Metis.Term.toString fol_tm)
-        fun tm_to_tt (Metis.Term.Var v) =
-               (case Recon.strip_prefix ResClause.tvar_prefix v of
-                    SOME w => Type (Recon.make_tvar w)
-                  | NONE =>
-                case Recon.strip_prefix ResClause.schematic_var_prefix v of
-                    SOME w => Term (mk_var (w, HOLogic.typeT))
-                  | NONE   => Term (mk_var (v, HOLogic.typeT)) )
-                      (*Var from Metis with a name like _nnn; possibly a type variable*)
-          | tm_to_tt (Metis.Term.Fn ("{}", [arg])) = tm_to_tt arg   (*hBOOL*)
-          | tm_to_tt (t as Metis.Term.Fn (".",_)) =
-              let val (rator,rands) = strip_happ [] t
-              in  case rator of
-                      Metis.Term.Fn(fname,ts) => applic_to_tt (fname, ts @ rands)
-                    | _ => case tm_to_tt rator of
-                               Term t => Term (list_comb(t, terms_of (map tm_to_tt rands)))
-                             | _ => error "tm_to_tt: HO application"
-              end
-          | tm_to_tt (Metis.Term.Fn (fname, args)) = applic_to_tt (fname,args)
-        and applic_to_tt ("=",ts) =
-              Term (list_comb(Const ("op =", HOLogic.typeT), terms_of (map tm_to_tt ts)))
-          | applic_to_tt (a,ts) =
-              case Recon.strip_prefix ResClause.const_prefix a of
-                  SOME b =>
-                    let val c = Recon.invert_const b
-                        val ntypes = Recon.num_typargs thy c
-                        val nterms = length ts - ntypes
-                        val tts = map tm_to_tt ts
-                        val tys = types_of (List.take(tts,ntypes))
-                        val ntyargs = Recon.num_typargs thy c
-                    in if length tys = ntyargs then
-                           apply_list (Const (c, dummyT)) nterms (List.drop(tts,ntypes))
-                       else error ("Constant " ^ c ^ " expects " ^ Int.toString ntyargs ^
-                                   " but gets " ^ Int.toString (length tys) ^
-                                   " type arguments\n" ^
-                                   cat_lines (map (Syntax.string_of_typ ctxt) tys) ^
-                                   " the terms are \n" ^
-                                   cat_lines (map (Syntax.string_of_term ctxt) (terms_of tts)))
-                       end
-                | NONE => (*Not a constant. Is it a type constructor?*)
-              case Recon.strip_prefix ResClause.tconst_prefix a of
-                  SOME b => Type (Term.Type(Recon.invert_type_const b, types_of (map tm_to_tt ts)))
-                | NONE => (*Maybe a TFree. Should then check that ts=[].*)
-              case Recon.strip_prefix ResClause.tfree_prefix a of
-                  SOME b => Type (mk_tfree ctxt b)
-                | NONE => (*a fixed variable? They are Skolem functions.*)
-              case Recon.strip_prefix ResClause.fixed_var_prefix a of
-                  SOME b =>
-                    let val opr = Term.Free(b, HOLogic.typeT)
-                    in  apply_list opr (length ts) (map tm_to_tt ts)  end
-                | NONE => error ("unexpected metis function: " ^ a)
-    in  case tm_to_tt fol_tm of Term t => t | _ => error "fol_tm_to_tt: Term expected"  end;
+(*Maps metis terms to isabelle terms*)
+fun fol_term_to_hol_RAW ctxt fol_tm =
+  let val thy = ProofContext.theory_of ctxt
+      val _ = trace_msg (fn () => "fol_term_to_hol: " ^ Metis.Term.toString fol_tm)
+      fun tm_to_tt (Metis.Term.Var v) =
+             (case Recon.strip_prefix ResClause.tvar_prefix v of
+                  SOME w => Type (Recon.make_tvar w)
+                | NONE =>
+              case Recon.strip_prefix ResClause.schematic_var_prefix v of
+                  SOME w => Term (mk_var (w, HOLogic.typeT))
+                | NONE   => Term (mk_var (v, HOLogic.typeT)) )
+                    (*Var from Metis with a name like _nnn; possibly a type variable*)
+        | tm_to_tt (Metis.Term.Fn ("{}", [arg])) = tm_to_tt arg   (*hBOOL*)
+        | tm_to_tt (t as Metis.Term.Fn (".",_)) =
+            let val (rator,rands) = strip_happ [] t
+            in  case rator of
+                    Metis.Term.Fn(fname,ts) => applic_to_tt (fname, ts @ rands)
+                  | _ => case tm_to_tt rator of
+                             Term t => Term (list_comb(t, terms_of (map tm_to_tt rands)))
+                           | _ => error "tm_to_tt: HO application"
+            end
+        | tm_to_tt (Metis.Term.Fn (fname, args)) = applic_to_tt (fname,args)
+      and applic_to_tt ("=",ts) =
+            Term (list_comb(Const ("op =", HOLogic.typeT), terms_of (map tm_to_tt ts)))
+        | applic_to_tt (a,ts) =
+            case Recon.strip_prefix ResClause.const_prefix a of
+                SOME b =>
+                  let val c = Recon.invert_const b
+                      val ntypes = Recon.num_typargs thy c
+                      val nterms = length ts - ntypes
+                      val tts = map tm_to_tt ts
+                      val tys = types_of (List.take(tts,ntypes))
+                      val ntyargs = Recon.num_typargs thy c
+                  in if length tys = ntyargs then
+                         apply_list (Const (c, dummyT)) nterms (List.drop(tts,ntypes))
+                     else error ("Constant " ^ c ^ " expects " ^ Int.toString ntyargs ^
+                                 " but gets " ^ Int.toString (length tys) ^
+                                 " type arguments\n" ^
+                                 cat_lines (map (Syntax.string_of_typ ctxt) tys) ^
+                                 " the terms are \n" ^
+                                 cat_lines (map (Syntax.string_of_term ctxt) (terms_of tts)))
+                     end
+              | NONE => (*Not a constant. Is it a type constructor?*)
+            case Recon.strip_prefix ResClause.tconst_prefix a of
+                SOME b => Type (Term.Type(Recon.invert_type_const b, types_of (map tm_to_tt ts)))
+              | NONE => (*Maybe a TFree. Should then check that ts=[].*)
+            case Recon.strip_prefix ResClause.tfree_prefix a of
+                SOME b => Type (mk_tfree ctxt b)
+              | NONE => (*a fixed variable? They are Skolem functions.*)
+            case Recon.strip_prefix ResClause.fixed_var_prefix a of
+                SOME b =>
+                  let val opr = Term.Free(b, HOLogic.typeT)
+                  in  apply_list opr (length ts) (map tm_to_tt ts)  end
+              | NONE => error ("unexpected metis function: " ^ a)
+  in  case tm_to_tt fol_tm of Term t => t | _ => error "fol_tm_to_tt: Term expected"  end;
 
-  (*Maps fully-typed metis terms to isabelle terms*)
-  fun fol_term_to_hol_FT ctxt fol_tm =
-    let val _ = trace_msg (fn () => "fol_term_to_hol_FT: " ^ Metis.Term.toString fol_tm)
-        fun cvt (Metis.Term.Fn ("ti", [Metis.Term.Var v, ty])) =
-               (case Recon.strip_prefix ResClause.schematic_var_prefix v of
-                    SOME w =>  mk_var(w, dummyT)
-                  | NONE   => mk_var(v, dummyT))
-          | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn ("=",[]), ty])) = 
-              Const ("op =", HOLogic.typeT)
-          | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn (x,[]), ty])) =
-             (case Recon.strip_prefix ResClause.const_prefix x of
-                  SOME c => Const (Recon.invert_const c, dummyT)
-                | NONE => (*Not a constant. Is it a fixed variable??*)
-              case Recon.strip_prefix ResClause.fixed_var_prefix x of
-                  SOME v => Free (v, fol_type_to_isa ctxt ty)
-                | NONE => error ("fol_term_to_hol_FT bad constant: " ^ x))
-          | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn (".",[tm1,tm2]), _])) =
-              cvt tm1 $ cvt tm2
-          | cvt (Metis.Term.Fn (".",[tm1,tm2])) = (*untyped application*)
-              cvt tm1 $ cvt tm2
-          | cvt (Metis.Term.Fn ("{}", [arg])) = cvt arg   (*hBOOL*)
-          | cvt (Metis.Term.Fn ("=", [tm1,tm2])) = 
-              list_comb(Const ("op =", HOLogic.typeT), map cvt [tm1,tm2])
-          | cvt (t as Metis.Term.Fn (x, [])) = 
-             (case Recon.strip_prefix ResClause.const_prefix x of
-                  SOME c => Const (Recon.invert_const c, dummyT)
-                | NONE => (*Not a constant. Is it a fixed variable??*)
-              case Recon.strip_prefix ResClause.fixed_var_prefix x of
-                  SOME v => Free (v, dummyT)
-                | NONE =>  (trace_msg (fn () => "fol_term_to_hol_FT bad const: " ^ x); fol_term_to_hol_RAW ctxt t))
-          | cvt t = (trace_msg (fn () => "fol_term_to_hol_FT bad term: " ^ Metis.Term.toString t); fol_term_to_hol_RAW ctxt t)
-    in  cvt fol_tm   end;
+(*Maps fully-typed metis terms to isabelle terms*)
+fun fol_term_to_hol_FT ctxt fol_tm =
+  let val _ = trace_msg (fn () => "fol_term_to_hol_FT: " ^ Metis.Term.toString fol_tm)
+      fun cvt (Metis.Term.Fn ("ti", [Metis.Term.Var v, ty])) =
+             (case Recon.strip_prefix ResClause.schematic_var_prefix v of
+                  SOME w =>  mk_var(w, dummyT)
+                | NONE   => mk_var(v, dummyT))
+        | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn ("=",[]), ty])) =
+            Const ("op =", HOLogic.typeT)
+        | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn (x,[]), ty])) =
+           (case Recon.strip_prefix ResClause.const_prefix x of
+                SOME c => Const (Recon.invert_const c, dummyT)
+              | NONE => (*Not a constant. Is it a fixed variable??*)
+            case Recon.strip_prefix ResClause.fixed_var_prefix x of
+                SOME v => Free (v, fol_type_to_isa ctxt ty)
+              | NONE => error ("fol_term_to_hol_FT bad constant: " ^ x))
+        | cvt (Metis.Term.Fn ("ti", [Metis.Term.Fn (".",[tm1,tm2]), _])) =
+            cvt tm1 $ cvt tm2
+        | cvt (Metis.Term.Fn (".",[tm1,tm2])) = (*untyped application*)
+            cvt tm1 $ cvt tm2
+        | cvt (Metis.Term.Fn ("{}", [arg])) = cvt arg   (*hBOOL*)
+        | cvt (Metis.Term.Fn ("=", [tm1,tm2])) =
+            list_comb(Const ("op =", HOLogic.typeT), map cvt [tm1,tm2])
+        | cvt (t as Metis.Term.Fn (x, [])) =
+           (case Recon.strip_prefix ResClause.const_prefix x of
+                SOME c => Const (Recon.invert_const c, dummyT)
+              | NONE => (*Not a constant. Is it a fixed variable??*)
+            case Recon.strip_prefix ResClause.fixed_var_prefix x of
+                SOME v => Free (v, dummyT)
+              | NONE =>  (trace_msg (fn () => "fol_term_to_hol_FT bad const: " ^ x); fol_term_to_hol_RAW ctxt t))
+        | cvt t = (trace_msg (fn () => "fol_term_to_hol_FT bad term: " ^ Metis.Term.toString t); fol_term_to_hol_RAW ctxt t)
+  in  cvt fol_tm   end;
 
-  fun fol_term_to_hol ctxt FO = fol_term_to_hol_RAW ctxt
-    | fol_term_to_hol ctxt HO = fol_term_to_hol_RAW ctxt
-    | fol_term_to_hol ctxt FT = fol_term_to_hol_FT ctxt;
+fun fol_term_to_hol ctxt FO = fol_term_to_hol_RAW ctxt
+  | fol_term_to_hol ctxt HO = fol_term_to_hol_RAW ctxt
+  | fol_term_to_hol ctxt FT = fol_term_to_hol_FT ctxt;
 
-  fun fol_terms_to_hol ctxt mode fol_tms =
-    let val ts = map (fol_term_to_hol ctxt mode) fol_tms
-        val _ = trace_msg (fn () => "  calling type inference:")
-        val _ = app (fn t => trace_msg (fn () => Syntax.string_of_term ctxt t)) ts
-        val ts' = infer_types ctxt ts;
-        val _ = app (fn t => trace_msg
-                      (fn () => "  final term: " ^ Syntax.string_of_term ctxt t ^
-                                "  of type  " ^ Syntax.string_of_typ ctxt (type_of t)))
-                    ts'
-    in  ts'  end;
+fun fol_terms_to_hol ctxt mode fol_tms =
+  let val ts = map (fol_term_to_hol ctxt mode) fol_tms
+      val _ = trace_msg (fn () => "  calling type inference:")
+      val _ = app (fn t => trace_msg (fn () => Syntax.string_of_term ctxt t)) ts
+      val ts' = infer_types ctxt ts;
+      val _ = app (fn t => trace_msg
+                    (fn () => "  final term: " ^ Syntax.string_of_term ctxt t ^
+                              "  of type  " ^ Syntax.string_of_typ ctxt (type_of t)))
+                  ts'
+  in  ts'  end;
 
-  fun mk_not (Const ("Not", _) $ b) = b
-    | mk_not b = HOLogic.mk_not b;
+fun mk_not (Const ("Not", _) $ b) = b
+  | mk_not b = HOLogic.mk_not b;
 
-  val metis_eq = Metis.Term.Fn ("=", []);
+val metis_eq = Metis.Term.Fn ("=", []);
 
-  (* ------------------------------------------------------------------------- *)
-  (* FOL step Inference Rules                                                  *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* FOL step Inference Rules                                                  *)
+(* ------------------------------------------------------------------------- *)
 
-  (*for debugging only*)
-  fun print_thpair (fth,th) =
-    (trace_msg (fn () => "=============================================");
-     trace_msg (fn () => "Metis: " ^ Metis.Thm.toString fth);
-     trace_msg (fn () => "Isabelle: " ^ Display.string_of_thm_without_context th));
+(*for debugging only*)
+fun print_thpair (fth,th) =
+  (trace_msg (fn () => "=============================================");
+   trace_msg (fn () => "Metis: " ^ Metis.Thm.toString fth);
+   trace_msg (fn () => "Isabelle: " ^ Display.string_of_thm_without_context th));
 
-  fun lookth thpairs (fth : Metis.Thm.thm) =
-    valOf (AList.lookup (uncurry Metis.Thm.equal) thpairs fth)
-    handle Option => error ("Failed to find a Metis theorem " ^ Metis.Thm.toString fth);
+fun lookth thpairs (fth : Metis.Thm.thm) =
+  valOf (AList.lookup (uncurry Metis.Thm.equal) thpairs fth)
+  handle Option => error ("Failed to find a Metis theorem " ^ Metis.Thm.toString fth);
 
-  fun is_TrueI th = Thm.eq_thm(TrueI,th);
+fun is_TrueI th = Thm.eq_thm(TrueI,th);
 
-  fun cterm_incr_types thy idx = cterm_of thy o (map_types (Logic.incr_tvar idx));
+fun cterm_incr_types thy idx = cterm_of thy o (map_types (Logic.incr_tvar idx));
 
-  fun inst_excluded_middle thy i_atm =
-    let val th = EXCLUDED_MIDDLE
-        val [vx] = Term.add_vars (prop_of th) []
-        val substs = [(cterm_of thy (Var vx), cterm_of thy i_atm)]
-    in  cterm_instantiate substs th  end;
+fun inst_excluded_middle thy i_atm =
+  let val th = EXCLUDED_MIDDLE
+      val [vx] = Term.add_vars (prop_of th) []
+      val substs = [(cterm_of thy (Var vx), cterm_of thy i_atm)]
+  in  cterm_instantiate substs th  end;
 
-  (* INFERENCE RULE: AXIOM *)
-  fun axiom_inf ctxt thpairs th = incr_indexes 1 (lookth thpairs th);
-      (*This causes variables to have an index of 1 by default. SEE ALSO mk_var above.*)
+(* INFERENCE RULE: AXIOM *)
+fun axiom_inf ctxt thpairs th = incr_indexes 1 (lookth thpairs th);
+    (*This causes variables to have an index of 1 by default. SEE ALSO mk_var above.*)
 
-  (* INFERENCE RULE: ASSUME *)
-  fun assume_inf ctxt mode atm =
-    inst_excluded_middle
-      (ProofContext.theory_of ctxt)
-      (singleton (fol_terms_to_hol ctxt mode) (Metis.Term.Fn atm));
+(* INFERENCE RULE: ASSUME *)
+fun assume_inf ctxt mode atm =
+  inst_excluded_middle
+    (ProofContext.theory_of ctxt)
+    (singleton (fol_terms_to_hol ctxt mode) (Metis.Term.Fn atm));
 
-  (* INFERENCE RULE: INSTANTIATE (Subst). Type instantiations are ignored. Trying to reconstruct
-     them admits new possibilities of errors, e.g. concerning sorts. Instead we try to arrange
-     that new TVars are distinct and that types can be inferred from terms.*)
-  fun inst_inf ctxt mode thpairs fsubst th =    
-    let val thy = ProofContext.theory_of ctxt
-        val i_th   = lookth thpairs th
-        val i_th_vars = Term.add_vars (prop_of i_th) []
-        fun find_var x = valOf (List.find (fn ((a,_),_) => a=x) i_th_vars)
-        fun subst_translation (x,y) =
-              let val v = find_var x
-                  val t = fol_term_to_hol ctxt mode y (*we call infer_types below*)
-              in  SOME (cterm_of thy (Var v), t)  end
-              handle Option =>
-                  (trace_msg (fn() => "List.find failed for the variable " ^ x ^
-                                         " in " ^ Display.string_of_thm ctxt i_th);
-                   NONE)
-        fun remove_typeinst (a, t) =
-              case Recon.strip_prefix ResClause.schematic_var_prefix a of
-                  SOME b => SOME (b, t)
-                | NONE   => case Recon.strip_prefix ResClause.tvar_prefix a of
-                  SOME _ => NONE          (*type instantiations are forbidden!*)
-                | NONE   => SOME (a,t)    (*internal Metis var?*)
-        val _ = trace_msg (fn () => "  isa th: " ^ Display.string_of_thm ctxt i_th)
-        val substs = map_filter remove_typeinst (Metis.Subst.toList fsubst)
-        val (vars,rawtms) = ListPair.unzip (map_filter subst_translation substs)
-        val tms = infer_types ctxt rawtms;
-        val ctm_of = cterm_incr_types thy (1 + Thm.maxidx_of i_th)
-        val substs' = ListPair.zip (vars, map ctm_of tms)
-        val _ = trace_msg (fn () =>
-          cat_lines ("subst_translations:" ::
-            (substs' |> map (fn (x, y) =>
-              Syntax.string_of_term ctxt (term_of x) ^ " |-> " ^
-              Syntax.string_of_term ctxt (term_of y)))));
-    in  cterm_instantiate substs' i_th  
-        handle THM (msg, _, _) => error ("metis error (inst_inf): " ^ msg)
-    end;
+(* INFERENCE RULE: INSTANTIATE (Subst). Type instantiations are ignored. Trying to reconstruct
+   them admits new possibilities of errors, e.g. concerning sorts. Instead we try to arrange
+   that new TVars are distinct and that types can be inferred from terms.*)
+fun inst_inf ctxt mode thpairs fsubst th =
+  let val thy = ProofContext.theory_of ctxt
+      val i_th   = lookth thpairs th
+      val i_th_vars = Term.add_vars (prop_of i_th) []
+      fun find_var x = valOf (List.find (fn ((a,_),_) => a=x) i_th_vars)
+      fun subst_translation (x,y) =
+            let val v = find_var x
+                val t = fol_term_to_hol ctxt mode y (*we call infer_types below*)
+            in  SOME (cterm_of thy (Var v), t)  end
+            handle Option =>
+                (trace_msg (fn() => "List.find failed for the variable " ^ x ^
+                                       " in " ^ Display.string_of_thm ctxt i_th);
+                 NONE)
+      fun remove_typeinst (a, t) =
+            case Recon.strip_prefix ResClause.schematic_var_prefix a of
+                SOME b => SOME (b, t)
+              | NONE   => case Recon.strip_prefix ResClause.tvar_prefix a of
+                SOME _ => NONE          (*type instantiations are forbidden!*)
+              | NONE   => SOME (a,t)    (*internal Metis var?*)
+      val _ = trace_msg (fn () => "  isa th: " ^ Display.string_of_thm ctxt i_th)
+      val substs = map_filter remove_typeinst (Metis.Subst.toList fsubst)
+      val (vars,rawtms) = ListPair.unzip (map_filter subst_translation substs)
+      val tms = infer_types ctxt rawtms;
+      val ctm_of = cterm_incr_types thy (1 + Thm.maxidx_of i_th)
+      val substs' = ListPair.zip (vars, map ctm_of tms)
+      val _ = trace_msg (fn () =>
+        cat_lines ("subst_translations:" ::
+          (substs' |> map (fn (x, y) =>
+            Syntax.string_of_term ctxt (term_of x) ^ " |-> " ^
+            Syntax.string_of_term ctxt (term_of y)))));
+  in  cterm_instantiate substs' i_th
+      handle THM (msg, _, _) => error ("metis error (inst_inf): " ^ msg)
+  end;
 
-  (* INFERENCE RULE: RESOLVE *)
+(* INFERENCE RULE: RESOLVE *)
 
-  (*Like RSN, but we rename apart only the type variables. Vars here typically have an index
-    of 1, and the use of RSN would increase this typically to 3. Instantiations of those Vars
-    could then fail. See comment on mk_var.*)
-  fun resolve_inc_tyvars(tha,i,thb) =
-    let val tha = Drule.incr_type_indexes (1 + Thm.maxidx_of thb) tha
-	val ths = Seq.list_of (Thm.bicompose false (false,tha,nprems_of tha) i thb)
-    in
-	case distinct Thm.eq_thm ths of
-	  [th] => th
-	| _ => raise THM ("resolve_inc_tyvars: unique result expected", i, [tha,thb])
-    end;
+(*Like RSN, but we rename apart only the type variables. Vars here typically have an index
+  of 1, and the use of RSN would increase this typically to 3. Instantiations of those Vars
+  could then fail. See comment on mk_var.*)
+fun resolve_inc_tyvars(tha,i,thb) =
+  let val tha = Drule.incr_type_indexes (1 + Thm.maxidx_of thb) tha
+      val ths = Seq.list_of (Thm.bicompose false (false,tha,nprems_of tha) i thb)
+  in
+      case distinct Thm.eq_thm ths of
+        [th] => th
+      | _ => raise THM ("resolve_inc_tyvars: unique result expected", i, [tha,thb])
+  end;
 
-  fun resolve_inf ctxt mode thpairs atm th1 th2 =
-    let
-      val thy = ProofContext.theory_of ctxt
-      val i_th1 = lookth thpairs th1 and i_th2 = lookth thpairs th2
-      val _ = trace_msg (fn () => "  isa th1 (pos): " ^ Display.string_of_thm ctxt i_th1)
-      val _ = trace_msg (fn () => "  isa th2 (neg): " ^ Display.string_of_thm ctxt i_th2)
-    in
-      if is_TrueI i_th1 then i_th2 (*Trivial cases where one operand is type info*)
-      else if is_TrueI i_th2 then i_th1
-      else
-        let
-          val i_atm = singleton (fol_terms_to_hol ctxt mode) (Metis.Term.Fn atm)
-          val _ = trace_msg (fn () => "  atom: " ^ Syntax.string_of_term ctxt i_atm)
-          val prems_th1 = prems_of i_th1
-          val prems_th2 = prems_of i_th2
-          val index_th1 = get_index (mk_not i_atm) prems_th1
-                handle Empty => error "Failed to find literal in th1"
-          val _ = trace_msg (fn () => "  index_th1: " ^ Int.toString index_th1)
-          val index_th2 = get_index i_atm prems_th2
-                handle Empty => error "Failed to find literal in th2"
-          val _ = trace_msg (fn () => "  index_th2: " ^ Int.toString index_th2)
-      in  resolve_inc_tyvars (Meson.select_literal index_th1 i_th1, index_th2, i_th2)  end
-    end;
+fun resolve_inf ctxt mode thpairs atm th1 th2 =
+  let
+    val thy = ProofContext.theory_of ctxt
+    val i_th1 = lookth thpairs th1 and i_th2 = lookth thpairs th2
+    val _ = trace_msg (fn () => "  isa th1 (pos): " ^ Display.string_of_thm ctxt i_th1)
+    val _ = trace_msg (fn () => "  isa th2 (neg): " ^ Display.string_of_thm ctxt i_th2)
+  in
+    if is_TrueI i_th1 then i_th2 (*Trivial cases where one operand is type info*)
+    else if is_TrueI i_th2 then i_th1
+    else
+      let
+        val i_atm = singleton (fol_terms_to_hol ctxt mode) (Metis.Term.Fn atm)
+        val _ = trace_msg (fn () => "  atom: " ^ Syntax.string_of_term ctxt i_atm)
+        val prems_th1 = prems_of i_th1
+        val prems_th2 = prems_of i_th2
+        val index_th1 = get_index (mk_not i_atm) prems_th1
+              handle Empty => error "Failed to find literal in th1"
+        val _ = trace_msg (fn () => "  index_th1: " ^ Int.toString index_th1)
+        val index_th2 = get_index i_atm prems_th2
+              handle Empty => error "Failed to find literal in th2"
+        val _ = trace_msg (fn () => "  index_th2: " ^ Int.toString index_th2)
+    in  resolve_inc_tyvars (Meson.select_literal index_th1 i_th1, index_th2, i_th2)  end
+  end;
 
-  (* INFERENCE RULE: REFL *)
-  val refl_x = cterm_of @{theory} (Var (hd (Term.add_vars (prop_of REFL_THM) [])));
-  val refl_idx = 1 + Thm.maxidx_of REFL_THM;
+(* INFERENCE RULE: REFL *)
+val refl_x = cterm_of @{theory} (Var (hd (Term.add_vars (prop_of REFL_THM) [])));
+val refl_idx = 1 + Thm.maxidx_of REFL_THM;
 
-  fun refl_inf ctxt mode t =
-    let val thy = ProofContext.theory_of ctxt
-        val i_t = singleton (fol_terms_to_hol ctxt mode) t
-        val _ = trace_msg (fn () => "  term: " ^ Syntax.string_of_term ctxt i_t)
-        val c_t = cterm_incr_types thy refl_idx i_t
-    in  cterm_instantiate [(refl_x, c_t)] REFL_THM  end;
+fun refl_inf ctxt mode t =
+  let val thy = ProofContext.theory_of ctxt
+      val i_t = singleton (fol_terms_to_hol ctxt mode) t
+      val _ = trace_msg (fn () => "  term: " ^ Syntax.string_of_term ctxt i_t)
+      val c_t = cterm_incr_types thy refl_idx i_t
+  in  cterm_instantiate [(refl_x, c_t)] REFL_THM  end;
 
-  fun get_ty_arg_size thy (Const("op =",_)) = 0  (*equality has no type arguments*)
-    | get_ty_arg_size thy (Const(c,_))      = (Recon.num_typargs thy c handle TYPE _ => 0)
-    | get_ty_arg_size thy _      = 0;
+fun get_ty_arg_size thy (Const("op =",_)) = 0  (*equality has no type arguments*)
+  | get_ty_arg_size thy (Const(c,_))      = (Recon.num_typargs thy c handle TYPE _ => 0)
+  | get_ty_arg_size thy _      = 0;
 
-  (* INFERENCE RULE: EQUALITY *)
-  fun equality_inf ctxt mode thpairs (pos,atm) fp fr =
-    let val thy = ProofContext.theory_of ctxt
-        val m_tm = Metis.Term.Fn atm
-        val [i_atm,i_tm] = fol_terms_to_hol ctxt mode [m_tm, fr]
-        val _ = trace_msg (fn () => "sign of the literal: " ^ Bool.toString pos)
-        fun replace_item_list lx 0 (l::ls) = lx::ls
-          | replace_item_list lx i (l::ls) = l :: replace_item_list lx (i-1) ls
-        fun path_finder_FO tm [] = (tm, Term.Bound 0)
-          | path_finder_FO tm (p::ps) =
-              let val (tm1,args) = Term.strip_comb tm
-                  val adjustment = get_ty_arg_size thy tm1
-                  val p' = if adjustment > p then p else p-adjustment
-                  val tm_p = List.nth(args,p')
-                    handle Subscript => error ("equality_inf: " ^ Int.toString p ^ " adj " ^
-                      Int.toString adjustment  ^ " term " ^  Syntax.string_of_term ctxt tm)
-                  val _ = trace_msg (fn () => "path_finder: " ^ Int.toString p ^
-                                        "  " ^ Syntax.string_of_term ctxt tm_p)
-		  val (r,t) = path_finder_FO tm_p ps
-              in
-                  (r, list_comb (tm1, replace_item_list t p' args)) 
-              end
-        fun path_finder_HO tm [] = (tm, Term.Bound 0)
-          | path_finder_HO (t$u) (0::ps) = (fn(x,y) => (x, y$u)) (path_finder_HO t ps)
-          | path_finder_HO (t$u) (p::ps) = (fn(x,y) => (x, t$y)) (path_finder_HO u ps)
-        fun path_finder_FT tm [] _ = (tm, Term.Bound 0)
-          | path_finder_FT tm (0::ps) (Metis.Term.Fn ("ti", [t1,t2])) = 
-              path_finder_FT tm ps t1
-          | path_finder_FT (t$u) (0::ps) (Metis.Term.Fn (".", [t1,t2])) = 
-              (fn(x,y) => (x, y$u)) (path_finder_FT t ps t1)
-          | path_finder_FT (t$u) (1::ps) (Metis.Term.Fn (".", [t1,t2])) = 
-              (fn(x,y) => (x, t$y)) (path_finder_FT u ps t2)
-          | path_finder_FT tm ps t = error ("equality_inf, path_finder_FT: path = " ^
-                                          space_implode " " (map Int.toString ps) ^ 
-                                          " isa-term: " ^  Syntax.string_of_term ctxt tm ^
-                                          " fol-term: " ^ Metis.Term.toString t)
-        fun path_finder FO tm ps _ = path_finder_FO tm ps
-          | path_finder HO (tm as Const("op =",_) $ _ $ _) (p::ps) _ =
-               (*equality: not curried, as other predicates are*)
-               if p=0 then path_finder_HO tm (0::1::ps)  (*select first operand*)
-               else path_finder_HO tm (p::ps)        (*1 selects second operand*)
-          | path_finder HO tm (p::ps) (Metis.Term.Fn ("{}", [t1])) =
-               path_finder_HO tm ps      (*if not equality, ignore head to skip hBOOL*)
-          | path_finder FT (tm as Const("op =",_) $ _ $ _) (p::ps) 
-                              (Metis.Term.Fn ("=", [t1,t2])) =
-               (*equality: not curried, as other predicates are*)
-               if p=0 then path_finder_FT tm (0::1::ps) 
-                            (Metis.Term.Fn (".", [Metis.Term.Fn (".", [metis_eq,t1]), t2])) 
-                            (*select first operand*)
-               else path_finder_FT tm (p::ps) 
-                     (Metis.Term.Fn (".", [metis_eq,t2])) 
-                     (*1 selects second operand*)
-          | path_finder FT tm (p::ps) (Metis.Term.Fn ("{}", [t1])) = path_finder_FT tm ps t1     
-               (*if not equality, ignore head to skip the hBOOL predicate*)
-          | path_finder FT tm ps t = path_finder_FT tm ps t  (*really an error case!*)
-        fun path_finder_lit ((nt as Term.Const ("Not", _)) $ tm_a) idx =
-              let val (tm, tm_rslt) = path_finder mode tm_a idx m_tm
-              in (tm, nt $ tm_rslt) end
-          | path_finder_lit tm_a idx = path_finder mode tm_a idx m_tm
-        val (tm_subst, body) = path_finder_lit i_atm fp
-        val tm_abs = Term.Abs("x", Term.type_of tm_subst, body)
-        val _ = trace_msg (fn () => "abstraction: " ^ Syntax.string_of_term ctxt tm_abs)
-        val _ = trace_msg (fn () => "i_tm: " ^ Syntax.string_of_term ctxt i_tm)
-        val _ = trace_msg (fn () => "located term: " ^ Syntax.string_of_term ctxt tm_subst)
-        val imax = maxidx_of_term (i_tm $ tm_abs $ tm_subst)  (*ill typed but gives right max*)
-        val subst' = incr_indexes (imax+1) (if pos then subst_em else ssubst_em)
-        val _ = trace_msg (fn () => "subst' " ^ Display.string_of_thm ctxt subst')
-        val eq_terms = map (pairself (cterm_of thy))
-                           (ListPair.zip (OldTerm.term_vars (prop_of subst'), [tm_abs, tm_subst, i_tm]))
-    in  cterm_instantiate eq_terms subst'  end;
+(* INFERENCE RULE: EQUALITY *)
+fun equality_inf ctxt mode thpairs (pos,atm) fp fr =
+  let val thy = ProofContext.theory_of ctxt
+      val m_tm = Metis.Term.Fn atm
+      val [i_atm,i_tm] = fol_terms_to_hol ctxt mode [m_tm, fr]
+      val _ = trace_msg (fn () => "sign of the literal: " ^ Bool.toString pos)
+      fun replace_item_list lx 0 (l::ls) = lx::ls
+        | replace_item_list lx i (l::ls) = l :: replace_item_list lx (i-1) ls
+      fun path_finder_FO tm [] = (tm, Term.Bound 0)
+        | path_finder_FO tm (p::ps) =
+            let val (tm1,args) = Term.strip_comb tm
+                val adjustment = get_ty_arg_size thy tm1
+                val p' = if adjustment > p then p else p-adjustment
+                val tm_p = List.nth(args,p')
+                  handle Subscript => error ("equality_inf: " ^ Int.toString p ^ " adj " ^
+                    Int.toString adjustment  ^ " term " ^  Syntax.string_of_term ctxt tm)
+                val _ = trace_msg (fn () => "path_finder: " ^ Int.toString p ^
+                                      "  " ^ Syntax.string_of_term ctxt tm_p)
+                val (r,t) = path_finder_FO tm_p ps
+            in
+                (r, list_comb (tm1, replace_item_list t p' args))
+            end
+      fun path_finder_HO tm [] = (tm, Term.Bound 0)
+        | path_finder_HO (t$u) (0::ps) = (fn(x,y) => (x, y$u)) (path_finder_HO t ps)
+        | path_finder_HO (t$u) (p::ps) = (fn(x,y) => (x, t$y)) (path_finder_HO u ps)
+      fun path_finder_FT tm [] _ = (tm, Term.Bound 0)
+        | path_finder_FT tm (0::ps) (Metis.Term.Fn ("ti", [t1,t2])) =
+            path_finder_FT tm ps t1
+        | path_finder_FT (t$u) (0::ps) (Metis.Term.Fn (".", [t1,t2])) =
+            (fn(x,y) => (x, y$u)) (path_finder_FT t ps t1)
+        | path_finder_FT (t$u) (1::ps) (Metis.Term.Fn (".", [t1,t2])) =
+            (fn(x,y) => (x, t$y)) (path_finder_FT u ps t2)
+        | path_finder_FT tm ps t = error ("equality_inf, path_finder_FT: path = " ^
+                                        space_implode " " (map Int.toString ps) ^
+                                        " isa-term: " ^  Syntax.string_of_term ctxt tm ^
+                                        " fol-term: " ^ Metis.Term.toString t)
+      fun path_finder FO tm ps _ = path_finder_FO tm ps
+        | path_finder HO (tm as Const("op =",_) $ _ $ _) (p::ps) _ =
+             (*equality: not curried, as other predicates are*)
+             if p=0 then path_finder_HO tm (0::1::ps)  (*select first operand*)
+             else path_finder_HO tm (p::ps)        (*1 selects second operand*)
+        | path_finder HO tm (p::ps) (Metis.Term.Fn ("{}", [t1])) =
+             path_finder_HO tm ps      (*if not equality, ignore head to skip hBOOL*)
+        | path_finder FT (tm as Const("op =",_) $ _ $ _) (p::ps)
+                            (Metis.Term.Fn ("=", [t1,t2])) =
+             (*equality: not curried, as other predicates are*)
+             if p=0 then path_finder_FT tm (0::1::ps)
+                          (Metis.Term.Fn (".", [Metis.Term.Fn (".", [metis_eq,t1]), t2]))
+                          (*select first operand*)
+             else path_finder_FT tm (p::ps)
+                   (Metis.Term.Fn (".", [metis_eq,t2]))
+                   (*1 selects second operand*)
+        | path_finder FT tm (p::ps) (Metis.Term.Fn ("{}", [t1])) = path_finder_FT tm ps t1
+             (*if not equality, ignore head to skip the hBOOL predicate*)
+        | path_finder FT tm ps t = path_finder_FT tm ps t  (*really an error case!*)
+      fun path_finder_lit ((nt as Term.Const ("Not", _)) $ tm_a) idx =
+            let val (tm, tm_rslt) = path_finder mode tm_a idx m_tm
+            in (tm, nt $ tm_rslt) end
+        | path_finder_lit tm_a idx = path_finder mode tm_a idx m_tm
+      val (tm_subst, body) = path_finder_lit i_atm fp
+      val tm_abs = Term.Abs("x", Term.type_of tm_subst, body)
+      val _ = trace_msg (fn () => "abstraction: " ^ Syntax.string_of_term ctxt tm_abs)
+      val _ = trace_msg (fn () => "i_tm: " ^ Syntax.string_of_term ctxt i_tm)
+      val _ = trace_msg (fn () => "located term: " ^ Syntax.string_of_term ctxt tm_subst)
+      val imax = maxidx_of_term (i_tm $ tm_abs $ tm_subst)  (*ill typed but gives right max*)
+      val subst' = incr_indexes (imax+1) (if pos then subst_em else ssubst_em)
+      val _ = trace_msg (fn () => "subst' " ^ Display.string_of_thm ctxt subst')
+      val eq_terms = map (pairself (cterm_of thy))
+                         (ListPair.zip (OldTerm.term_vars (prop_of subst'), [tm_abs, tm_subst, i_tm]))
+  in  cterm_instantiate eq_terms subst'  end;
 
-  val factor = Seq.hd o distinct_subgoals_tac;
+val factor = Seq.hd o distinct_subgoals_tac;
 
-  fun step ctxt mode thpairs (fol_th, Metis.Proof.Axiom _)                        =
-        factor (axiom_inf ctxt thpairs fol_th)
-    | step ctxt mode thpairs (_, Metis.Proof.Assume f_atm)                        =
-        assume_inf ctxt mode f_atm
-    | step ctxt mode thpairs (_, Metis.Proof.Subst(f_subst, f_th1))               =
-        factor (inst_inf ctxt mode thpairs f_subst f_th1)
-    | step ctxt mode thpairs (_, Metis.Proof.Resolve(f_atm, f_th1, f_th2))        =
-        factor (resolve_inf ctxt mode thpairs f_atm f_th1 f_th2)
-    | step ctxt mode thpairs (_, Metis.Proof.Refl f_tm)                           =
-        refl_inf ctxt mode f_tm
-    | step ctxt mode thpairs (_, Metis.Proof.Equality(f_lit, f_p, f_r)) =
-        equality_inf ctxt mode thpairs f_lit f_p f_r;
+fun step ctxt mode thpairs (fol_th, Metis.Proof.Axiom _)                        =
+      factor (axiom_inf ctxt thpairs fol_th)
+  | step ctxt mode thpairs (_, Metis.Proof.Assume f_atm)                        =
+      assume_inf ctxt mode f_atm
+  | step ctxt mode thpairs (_, Metis.Proof.Subst(f_subst, f_th1))               =
+      factor (inst_inf ctxt mode thpairs f_subst f_th1)
+  | step ctxt mode thpairs (_, Metis.Proof.Resolve(f_atm, f_th1, f_th2))        =
+      factor (resolve_inf ctxt mode thpairs f_atm f_th1 f_th2)
+  | step ctxt mode thpairs (_, Metis.Proof.Refl f_tm)                           =
+      refl_inf ctxt mode f_tm
+  | step ctxt mode thpairs (_, Metis.Proof.Equality(f_lit, f_p, f_r)) =
+      equality_inf ctxt mode thpairs f_lit f_p f_r;
 
-  fun real_literal (b, (c, _)) = not (String.isPrefix ResClause.class_prefix c);
+fun real_literal (b, (c, _)) = not (String.isPrefix ResClause.class_prefix c);
 
-  fun translate mode _    thpairs [] = thpairs
-    | translate mode ctxt thpairs ((fol_th, inf) :: infpairs) =
-        let val _ = trace_msg (fn () => "=============================================")
-            val _ = trace_msg (fn () => "METIS THM: " ^ Metis.Thm.toString fol_th)
-            val _ = trace_msg (fn () => "INFERENCE: " ^ Metis.Proof.inferenceToString inf)
-            val th = Meson.flexflex_first_order (step ctxt mode thpairs (fol_th, inf))
-            val _ = trace_msg (fn () => "ISABELLE THM: " ^ Display.string_of_thm ctxt th)
-            val _ = trace_msg (fn () => "=============================================")
-            val n_metis_lits = length (filter real_literal (Metis.LiteralSet.toList (Metis.Thm.clause fol_th)))
-        in
-            if nprems_of th = n_metis_lits then ()
-            else error "Metis: proof reconstruction has gone wrong";
-            translate mode ctxt ((fol_th, th) :: thpairs) infpairs
-        end;
+fun translate mode _    thpairs [] = thpairs
+  | translate mode ctxt thpairs ((fol_th, inf) :: infpairs) =
+      let val _ = trace_msg (fn () => "=============================================")
+          val _ = trace_msg (fn () => "METIS THM: " ^ Metis.Thm.toString fol_th)
+          val _ = trace_msg (fn () => "INFERENCE: " ^ Metis.Proof.inferenceToString inf)
+          val th = Meson.flexflex_first_order (step ctxt mode thpairs (fol_th, inf))
+          val _ = trace_msg (fn () => "ISABELLE THM: " ^ Display.string_of_thm ctxt th)
+          val _ = trace_msg (fn () => "=============================================")
+          val n_metis_lits = length (filter real_literal (Metis.LiteralSet.toList (Metis.Thm.clause fol_th)))
+      in
+          if nprems_of th = n_metis_lits then ()
+          else error "Metis: proof reconstruction has gone wrong";
+          translate mode ctxt ((fol_th, th) :: thpairs) infpairs
+      end;
 
-  (*Determining which axiom clauses are actually used*)
-  fun used_axioms axioms (th, Metis.Proof.Axiom _) = SOME (lookth axioms th)
-    | used_axioms axioms _                         = NONE;
+(*Determining which axiom clauses are actually used*)
+fun used_axioms axioms (th, Metis.Proof.Axiom _) = SOME (lookth axioms th)
+  | used_axioms axioms _                         = NONE;
 
-  (* ------------------------------------------------------------------------- *)
-  (* Translation of HO Clauses                                                 *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* Translation of HO Clauses                                                 *)
+(* ------------------------------------------------------------------------- *)
 
-  fun cnf_th thy th = hd (ResAxioms.cnf_axiom thy th);
+fun cnf_th thy th = hd (ResAxioms.cnf_axiom thy th);
 
-  val equal_imp_fequal' = cnf_th @{theory} @{thm equal_imp_fequal};
-  val fequal_imp_equal' = cnf_th @{theory} @{thm fequal_imp_equal};
+val equal_imp_fequal' = cnf_th @{theory} @{thm equal_imp_fequal};
+val fequal_imp_equal' = cnf_th @{theory} @{thm fequal_imp_equal};
 
-  val comb_I = cnf_th @{theory} ResHolClause.comb_I;
-  val comb_K = cnf_th @{theory} ResHolClause.comb_K;
-  val comb_B = cnf_th @{theory} ResHolClause.comb_B;
-  val comb_C = cnf_th @{theory} ResHolClause.comb_C;
-  val comb_S = cnf_th @{theory} ResHolClause.comb_S;
+val comb_I = cnf_th @{theory} ResHolClause.comb_I;
+val comb_K = cnf_th @{theory} ResHolClause.comb_K;
+val comb_B = cnf_th @{theory} ResHolClause.comb_B;
+val comb_C = cnf_th @{theory} ResHolClause.comb_C;
+val comb_S = cnf_th @{theory} ResHolClause.comb_S;
 
-  fun type_ext thy tms =
-    let val subs = ResAtp.tfree_classes_of_terms tms
-        val supers = ResAtp.tvar_classes_of_terms tms
-        and tycons = ResAtp.type_consts_of_terms thy tms
-        val arity_clauses = ResClause.make_arity_clauses thy tycons supers
-        val (supers',arity_clauses) = ResClause.make_arity_clauses thy tycons supers
-        val classrel_clauses = ResClause.make_classrel_clauses thy subs supers'
-    in  map classrel_cls classrel_clauses @ map arity_cls arity_clauses
-    end;
+fun type_ext thy tms =
+  let val subs = ResAtp.tfree_classes_of_terms tms
+      val supers = ResAtp.tvar_classes_of_terms tms
+      and tycons = ResAtp.type_consts_of_terms thy tms
+      val arity_clauses = ResClause.make_arity_clauses thy tycons supers
+      val (supers',arity_clauses) = ResClause.make_arity_clauses thy tycons supers
+      val classrel_clauses = ResClause.make_classrel_clauses thy subs supers'
+  in  map classrel_cls classrel_clauses @ map arity_cls arity_clauses
+  end;
 
-  (* ------------------------------------------------------------------------- *)
-  (* Logic maps manage the interface between HOL and first-order logic.        *)
-  (* ------------------------------------------------------------------------- *)
+(* ------------------------------------------------------------------------- *)
+(* Logic maps manage the interface between HOL and first-order logic.        *)
+(* ------------------------------------------------------------------------- *)
 
-  type logic_map =
-    {axioms : (Metis.Thm.thm * Thm.thm) list,
-     tfrees : ResClause.type_literal list};
+type logic_map =
+  {axioms : (Metis.Thm.thm * Thm.thm) list,
+   tfrees : ResClause.type_literal list};
 
-  fun const_in_metis c (pol,(pred,tm_list)) =
-    let
-      fun in_mterm (Metis.Term.Var nm) = false
-        | in_mterm (Metis.Term.Fn (".", tm_list)) = exists in_mterm tm_list
-        | in_mterm (Metis.Term.Fn (nm, tm_list)) = c=nm orelse exists in_mterm tm_list
-    in  c=pred orelse exists in_mterm tm_list  end;
+fun const_in_metis c (pol,(pred,tm_list)) =
+  let
+    fun in_mterm (Metis.Term.Var nm) = false
+      | in_mterm (Metis.Term.Fn (".", tm_list)) = exists in_mterm tm_list
+      | in_mterm (Metis.Term.Fn (nm, tm_list)) = c=nm orelse exists in_mterm tm_list
+  in  c=pred orelse exists in_mterm tm_list  end;
 
-  (*Extract TFree constraints from context to include as conjecture clauses*)
-  fun init_tfrees ctxt =
-    let fun add ((a,i),s) Ts = if i = ~1 then TFree(a,s) :: Ts else Ts
-    in  ResClause.add_typs (Vartab.fold add (#2 (Variable.constraints_of ctxt)) []) end;
+(*Extract TFree constraints from context to include as conjecture clauses*)
+fun init_tfrees ctxt =
+  let fun add ((a,i),s) Ts = if i = ~1 then TFree(a,s) :: Ts else Ts
+  in  ResClause.add_typs (Vartab.fold add (#2 (Variable.constraints_of ctxt)) []) end;
 
-  (*transform isabelle type / arity clause to metis clause *)
-  fun add_type_thm [] lmap = lmap
-    | add_type_thm ((ith, mth) :: cls) {axioms, tfrees} =
-        add_type_thm cls {axioms = (mth, ith) :: axioms,
-                          tfrees = tfrees}
+(*transform isabelle type / arity clause to metis clause *)
+fun add_type_thm [] lmap = lmap
+  | add_type_thm ((ith, mth) :: cls) {axioms, tfrees} =
+      add_type_thm cls {axioms = (mth, ith) :: axioms,
+                        tfrees = tfrees}
 
-  (*Insert non-logical axioms corresponding to all accumulated TFrees*)
-  fun add_tfrees {axioms, tfrees} : logic_map =
-       {axioms = (map (fn tf => (metis_of_tfree tf, TrueI)) (distinct op= tfrees)) @ axioms,
-        tfrees = tfrees};
+(*Insert non-logical axioms corresponding to all accumulated TFrees*)
+fun add_tfrees {axioms, tfrees} : logic_map =
+     {axioms = (map (fn tf => (metis_of_tfree tf, TrueI)) (distinct op= tfrees)) @ axioms,
+      tfrees = tfrees};
 
-  fun string_of_mode FO = "FO"
-    | string_of_mode HO = "HO"
-    | string_of_mode FT = "FT"
+fun string_of_mode FO = "FO"
+  | string_of_mode HO = "HO"
+  | string_of_mode FT = "FT"
 
-  (* Function to generate metis clauses, including comb and type clauses *)
-  fun build_map mode0 ctxt cls ths =
-    let val thy = ProofContext.theory_of ctxt
-        (*The modes FO and FT are sticky. HO can be downgraded to FO.*)
-	fun set_mode FO = FO
-	  | set_mode HO = if forall (Meson.is_fol_term thy o prop_of) (cls@ths) then FO else HO
-	  | set_mode FT = FT
-        val mode = set_mode mode0 
-	(*transform isabelle clause to metis clause *)
-	fun add_thm is_conjecture (ith, {axioms, tfrees}) : logic_map =
-	  let val (mth, tfree_lits) = hol_thm_to_fol is_conjecture ctxt mode ith
-	  in
-	     {axioms = (mth, Meson.make_meta_clause ith) :: axioms,
-	      tfrees = tfree_lits union tfrees}
-	  end;
-        val lmap0 = List.foldl (add_thm true)
-                          {axioms = [], tfrees = init_tfrees ctxt} cls
-        val lmap = List.foldl (add_thm false) (add_tfrees lmap0) ths
-        val clause_lists = map (Metis.Thm.clause o #1) (#axioms lmap)
-        fun used c = exists (Metis.LiteralSet.exists (const_in_metis c)) clause_lists
-        (*Now check for the existence of certain combinators*)
-        val thI  = if used "c_COMBI" then [comb_I] else []
-        val thK  = if used "c_COMBK" then [comb_K] else []
-        val thB   = if used "c_COMBB" then [comb_B] else []
-        val thC   = if used "c_COMBC" then [comb_C] else []
-        val thS   = if used "c_COMBS" then [comb_S] else []
-        val thEQ  = if used "c_fequal" then [fequal_imp_equal', equal_imp_fequal'] else []
-        val lmap' = if mode=FO then lmap
-                    else List.foldl (add_thm false) lmap (thEQ @ thS @ thC @ thB @ thK @ thI)
-    in
-        (mode, add_type_thm (type_ext thy (map prop_of (cls @ ths))) lmap')
-    end;
+(* Function to generate metis clauses, including comb and type clauses *)
+fun build_map mode0 ctxt cls ths =
+  let val thy = ProofContext.theory_of ctxt
+      (*The modes FO and FT are sticky. HO can be downgraded to FO.*)
+      fun set_mode FO = FO
+        | set_mode HO = if forall (Meson.is_fol_term thy o prop_of) (cls@ths) then FO else HO
+        | set_mode FT = FT
+      val mode = set_mode mode0
+      (*transform isabelle clause to metis clause *)
+      fun add_thm is_conjecture (ith, {axioms, tfrees}) : logic_map =
+        let val (mth, tfree_lits) = hol_thm_to_fol is_conjecture ctxt mode ith
+        in
+           {axioms = (mth, Meson.make_meta_clause ith) :: axioms,
+            tfrees = tfree_lits union tfrees}
+        end;
+      val lmap0 = List.foldl (add_thm true)
+                        {axioms = [], tfrees = init_tfrees ctxt} cls
+      val lmap = List.foldl (add_thm false) (add_tfrees lmap0) ths
+      val clause_lists = map (Metis.Thm.clause o #1) (#axioms lmap)
+      fun used c = exists (Metis.LiteralSet.exists (const_in_metis c)) clause_lists
+      (*Now check for the existence of certain combinators*)
+      val thI  = if used "c_COMBI" then [comb_I] else []
+      val thK  = if used "c_COMBK" then [comb_K] else []
+      val thB   = if used "c_COMBB" then [comb_B] else []
+      val thC   = if used "c_COMBC" then [comb_C] else []
+      val thS   = if used "c_COMBS" then [comb_S] else []
+      val thEQ  = if used "c_fequal" then [fequal_imp_equal', equal_imp_fequal'] else []
+      val lmap' = if mode=FO then lmap
+                  else List.foldl (add_thm false) lmap (thEQ @ thS @ thC @ thB @ thK @ thI)
+  in
+      (mode, add_type_thm (type_ext thy (map prop_of (cls @ ths))) lmap')
+  end;
 
-  fun refute cls =
-      Metis.Resolution.loop (Metis.Resolution.new Metis.Resolution.default cls);
+fun refute cls =
+    Metis.Resolution.loop (Metis.Resolution.new Metis.Resolution.default cls);
 
-  fun is_false t = t aconv (HOLogic.mk_Trueprop HOLogic.false_const);
+fun is_false t = t aconv (HOLogic.mk_Trueprop HOLogic.false_const);
 
-  fun common_thm ths1 ths2 = exists (member Thm.eq_thm ths1) (map Meson.make_meta_clause ths2);
+fun common_thm ths1 ths2 = exists (member Thm.eq_thm ths1) (map Meson.make_meta_clause ths2);
 
-  exception METIS of string;
+exception METIS of string;
 
-  (* Main function to start metis prove and reconstruction *)
-  fun FOL_SOLVE mode ctxt cls ths0 =
-    let val thy = ProofContext.theory_of ctxt
-        val th_cls_pairs = map (fn th => (Thm.get_name_hint th, ResAxioms.cnf_axiom thy th)) ths0
-        val ths = maps #2 th_cls_pairs
-        val _ = trace_msg (fn () => "FOL_SOLVE: CONJECTURE CLAUSES")
-        val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) cls
-        val _ = trace_msg (fn () => "THEOREM CLAUSES")
-        val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) ths
-        val (mode, {axioms,tfrees}) = build_map mode ctxt cls ths
-        val _ = if null tfrees then ()
-                else (trace_msg (fn () => "TFREE CLAUSES");
-                      app (fn tf => trace_msg (fn _ => ResClause.tptp_of_typeLit true tf)) tfrees)
-        val _ = trace_msg (fn () => "CLAUSES GIVEN TO METIS")
-        val thms = map #1 axioms
-        val _ = app (fn th => trace_msg (fn () => Metis.Thm.toString th)) thms
-        val _ = trace_msg (fn () => "mode = " ^ string_of_mode mode)
-        val _ = trace_msg (fn () => "START METIS PROVE PROCESS")
-    in
-        case List.filter (is_false o prop_of) cls of
-            false_th::_ => [false_th RS @{thm FalseE}]
-          | [] =>
-        case refute thms of
-            Metis.Resolution.Contradiction mth =>
-              let val _ = trace_msg (fn () => "METIS RECONSTRUCTION START: " ^
-                            Metis.Thm.toString mth)
-                  val ctxt' = fold Variable.declare_constraints (map prop_of cls) ctxt
-                               (*add constraints arising from converting goal to clause form*)
-                  val proof = Metis.Proof.proof mth
-                  val result = translate mode ctxt' axioms proof
-                  and used = map_filter (used_axioms axioms) proof
-                  val _ = trace_msg (fn () => "METIS COMPLETED...clauses actually used:")
-	          val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) used
-	          val unused = filter (fn (a,cls) => not (common_thm used cls)) th_cls_pairs
-              in
-                  if null unused then ()
-                  else warning ("Metis: unused theorems " ^ commas_quote (map #1 unused));
-                  case result of
-                      (_,ith)::_ => 
-                          (trace_msg (fn () => "success: " ^ Display.string_of_thm ctxt ith); 
-                           [ith])
-                    | _ => (trace_msg (fn () => "Metis: no result"); 
-                            [])
-              end
-          | Metis.Resolution.Satisfiable _ => 
-	      (trace_msg (fn () => "Metis: No first-order proof with the lemmas supplied"); 
-	       [])
-    end;
+(* Main function to start metis prove and reconstruction *)
+fun FOL_SOLVE mode ctxt cls ths0 =
+  let val thy = ProofContext.theory_of ctxt
+      val th_cls_pairs = map (fn th => (Thm.get_name_hint th, ResAxioms.cnf_axiom thy th)) ths0
+      val ths = maps #2 th_cls_pairs
+      val _ = trace_msg (fn () => "FOL_SOLVE: CONJECTURE CLAUSES")
+      val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) cls
+      val _ = trace_msg (fn () => "THEOREM CLAUSES")
+      val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) ths
+      val (mode, {axioms,tfrees}) = build_map mode ctxt cls ths
+      val _ = if null tfrees then ()
+              else (trace_msg (fn () => "TFREE CLAUSES");
+                    app (fn tf => trace_msg (fn _ => ResClause.tptp_of_typeLit true tf)) tfrees)
+      val _ = trace_msg (fn () => "CLAUSES GIVEN TO METIS")
+      val thms = map #1 axioms
+      val _ = app (fn th => trace_msg (fn () => Metis.Thm.toString th)) thms
+      val _ = trace_msg (fn () => "mode = " ^ string_of_mode mode)
+      val _ = trace_msg (fn () => "START METIS PROVE PROCESS")
+  in
+      case List.filter (is_false o prop_of) cls of
+          false_th::_ => [false_th RS @{thm FalseE}]
+        | [] =>
+      case refute thms of
+          Metis.Resolution.Contradiction mth =>
+            let val _ = trace_msg (fn () => "METIS RECONSTRUCTION START: " ^
+                          Metis.Thm.toString mth)
+                val ctxt' = fold Variable.declare_constraints (map prop_of cls) ctxt
+                             (*add constraints arising from converting goal to clause form*)
+                val proof = Metis.Proof.proof mth
+                val result = translate mode ctxt' axioms proof
+                and used = map_filter (used_axioms axioms) proof
+                val _ = trace_msg (fn () => "METIS COMPLETED...clauses actually used:")
+                val _ = app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th)) used
+                val unused = filter (fn (a,cls) => not (common_thm used cls)) th_cls_pairs
+            in
+                if null unused then ()
+                else warning ("Metis: unused theorems " ^ commas_quote (map #1 unused));
+                case result of
+                    (_,ith)::_ =>
+                        (trace_msg (fn () => "success: " ^ Display.string_of_thm ctxt ith);
+                         [ith])
+                  | _ => (trace_msg (fn () => "Metis: no result");
+                          [])
+            end
+        | Metis.Resolution.Satisfiable _ =>
+            (trace_msg (fn () => "Metis: No first-order proof with the lemmas supplied");
+             [])
+  end;
 
-  fun metis_general_tac mode ctxt ths i st0 =
-    let val _ = trace_msg (fn () =>
-          "Metis called with theorems " ^ cat_lines (map (Display.string_of_thm ctxt) ths))
-    in
-       if exists_type ResAxioms.type_has_empty_sort (prop_of st0)  
-       then (warning "Proof state contains the empty sort"; Seq.empty)
-       else 
-	 (Meson.MESON ResAxioms.neg_clausify
-	   (fn cls => resolve_tac (FOL_SOLVE mode ctxt cls ths) 1) ctxt i
-	  THEN ResAxioms.expand_defs_tac st0) st0
-    end
-    handle METIS s => (warning ("Metis: " ^ s); Seq.empty);
+fun metis_general_tac mode ctxt ths i st0 =
+  let val _ = trace_msg (fn () =>
+        "Metis called with theorems " ^ cat_lines (map (Display.string_of_thm ctxt) ths))
+  in
+     if exists_type ResAxioms.type_has_empty_sort (prop_of st0)
+     then (warning "Proof state contains the empty sort"; Seq.empty)
+     else
+       (Meson.MESON ResAxioms.neg_clausify
+         (fn cls => resolve_tac (FOL_SOLVE mode ctxt cls ths) 1) ctxt i
+        THEN ResAxioms.expand_defs_tac st0) st0
+  end
+  handle METIS s => (warning ("Metis: " ^ s); Seq.empty);
 
-  val metis_tac = metis_general_tac HO;
-  val metisF_tac = metis_general_tac FO;
-  val metisFT_tac = metis_general_tac FT;
+val metis_tac = metis_general_tac HO;
+val metisF_tac = metis_general_tac FO;
+val metisFT_tac = metis_general_tac FT;
 
-  fun method name mode comment = Method.setup name (Attrib.thms >> (fn ths => fn ctxt =>
-    SIMPLE_METHOD' (CHANGED_PROP o metis_general_tac mode ctxt ths))) comment;
+fun method name mode comment = Method.setup name (Attrib.thms >> (fn ths => fn ctxt =>
+  SIMPLE_METHOD' (CHANGED_PROP o metis_general_tac mode ctxt ths))) comment;
 
-  val setup =
-    type_lits_setup #>
-    method @{binding metis} HO "METIS for FOL & HOL problems" #>
-    method @{binding metisF} FO "METIS for FOL problems" #>
-    method @{binding metisFT} FT "METIS With-fully typed translation" #>
-    Method.setup @{binding finish_clausify}
-      (Scan.succeed (K (SIMPLE_METHOD (ResAxioms.expand_defs_tac refl))))
-      "cleanup after conversion to clauses";
+val setup =
+  type_lits_setup #>
+  method @{binding metis} HO "METIS for FOL & HOL problems" #>
+  method @{binding metisF} FO "METIS for FOL problems" #>
+  method @{binding metisFT} FT "METIS With-fully typed translation" #>
+  Method.setup @{binding finish_clausify}
+    (Scan.succeed (K (SIMPLE_METHOD (ResAxioms.expand_defs_tac refl))))
+    "cleanup after conversion to clauses";
 
 end;