move Metis into Plain
authorblanchet
Mon, 04 Oct 2010 22:45:09 +0200
changeset 39946 78faa9b31202
parent 39945 277addece9b7
child 39947 f95834c8bb4d
move Metis into Plain
src/HOL/IsaMakefile
src/HOL/List.thy
src/HOL/Meson.thy
src/HOL/Metis.thy
src/HOL/Plain.thy
src/HOL/Quotient.thy
src/HOL/Refute.thy
src/HOL/Sledgehammer.thy
src/HOL/Tools/Metis/metis_reconstruct.ML
src/HOL/Tools/Metis/metis_tactics.ML
src/HOL/Tools/Metis/metis_translate.ML
src/HOL/Tools/Sledgehammer/metis_reconstruct.ML
src/HOL/Tools/Sledgehammer/metis_tactics.ML
src/HOL/Tools/Sledgehammer/metis_translate.ML
src/HOL/Tools/Sledgehammer/sledgehammer_filter.ML
--- a/src/HOL/IsaMakefile	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/IsaMakefile	Mon Oct 04 22:45:09 2010 +0200
@@ -155,6 +155,7 @@
   Inductive.thy \
   Lattices.thy \
   Meson.thy \
+  Metis.thy \
   Nat.thy \
   Option.thy \
   Orderings.thy \
@@ -204,6 +205,9 @@
   Tools/lin_arith.ML \
   Tools/Meson/meson.ML \
   Tools/Meson/meson_clausify.ML \
+  Tools/Metis/metis_reconstruct.ML \
+  Tools/Metis/metis_translate.ML \
+  Tools/Metis/metis_tactics.ML \
   Tools/nat_arith.ML \
   Tools/primrec.ML \
   Tools/prop_logic.ML \
@@ -222,6 +226,7 @@
   $(SRC)/Provers/Arith/fast_lin_arith.ML \
   $(SRC)/Provers/order.ML \
   $(SRC)/Provers/trancl.ML \
+  $(SRC)/Tools/Metis/metis.ML \
   $(SRC)/Tools/rat.ML
 
 $(OUT)/HOL-Plain: plain.ML $(PLAIN_DEPENDENCIES)
@@ -267,7 +272,6 @@
   $(SRC)/Provers/Arith/cancel_numerals.ML \
   $(SRC)/Provers/Arith/combine_numerals.ML \
   $(SRC)/Provers/Arith/extract_common_term.ML \
-  $(SRC)/Tools/Metis/metis.ML \
   Tools/async_manager.ML \
   Tools/ATP/atp_problem.ML \
   Tools/ATP/atp_proof.ML \
@@ -317,9 +321,6 @@
   Tools/recdef.ML \
   Tools/record.ML \
   Tools/semiring_normalizer.ML \
-  Tools/Sledgehammer/metis_reconstruct.ML \
-  Tools/Sledgehammer/metis_translate.ML \
-  Tools/Sledgehammer/metis_tactics.ML \
   Tools/Sledgehammer/sledgehammer.ML \
   Tools/Sledgehammer/sledgehammer_filter.ML \
   Tools/Sledgehammer/sledgehammer_minimize.ML \
--- a/src/HOL/List.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/List.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -5,7 +5,7 @@
 header {* The datatype of finite lists *}
 
 theory List
-imports Plain Quotient Presburger Code_Numeral Sledgehammer Recdef
+imports Plain Quotient Presburger Code_Numeral Recdef
 uses ("Tools/list_code.ML")
 begin
 
--- a/src/HOL/Meson.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Meson.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -8,7 +8,7 @@
 header {* MESON Proof Procedure (Model Elimination) *}
 
 theory Meson
-imports Nat
+imports Datatype
 uses ("Tools/Meson/meson.ML")
      ("Tools/Meson/meson_clausify.ML")
 begin
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Metis.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -0,0 +1,35 @@
+(*  Title:      HOL/Metis.thy
+    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
+    Author:     Jia Meng, Cambridge University Computer Laboratory and NICTA
+    Author:     Jasmin Blanchette, TU Muenchen
+*)
+
+header {* Metis Proof Method *}
+
+theory Metis
+imports Meson
+uses "~~/src/Tools/Metis/metis.ML"
+     ("Tools/Metis/metis_translate.ML")
+     ("Tools/Metis/metis_reconstruct.ML")
+     ("Tools/Metis/metis_tactics.ML")
+begin
+
+definition fequal :: "'a \<Rightarrow> 'a \<Rightarrow> bool" where [no_atp]:
+"fequal X Y \<longleftrightarrow> (X = Y)"
+
+lemma fequal_imp_equal [no_atp]: "\<not> fequal X Y \<or> X = Y"
+by (simp add: fequal_def)
+
+lemma equal_imp_fequal [no_atp]: "\<not> X = Y \<or> fequal X Y"
+by (simp add: fequal_def)
+
+lemma equal_imp_equal [no_atp]: "X = Y ==> X = Y"
+by auto
+
+use "Tools/Metis/metis_translate.ML"
+use "Tools/Metis/metis_reconstruct.ML"
+use "Tools/Metis/metis_tactics.ML"
+
+setup Metis_Tactics.setup
+
+end
--- a/src/HOL/Plain.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Plain.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -1,7 +1,7 @@
 header {* Plain HOL *}
 
 theory Plain
-imports Datatype FunDef Extraction Meson
+imports Datatype FunDef Extraction Metis
 begin
 
 text {*
--- a/src/HOL/Quotient.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Quotient.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -5,7 +5,7 @@
 header {* Definition of Quotient Types *}
 
 theory Quotient
-imports Plain Sledgehammer
+imports Plain Hilbert_Choice
 uses
   ("Tools/Quotient/quotient_info.ML")
   ("Tools/Quotient/quotient_typ.ML")
--- a/src/HOL/Refute.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Refute.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -8,7 +8,7 @@
 header {* Refute *}
 
 theory Refute
-imports Hilbert_Choice List
+imports Hilbert_Choice List Sledgehammer
 uses "Tools/refute.ML"
 begin
 
--- a/src/HOL/Sledgehammer.thy	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Sledgehammer.thy	Mon Oct 04 22:45:09 2010 +0200
@@ -8,15 +8,11 @@
 header {* Sledgehammer: Isabelle--ATP Linkup *}
 
 theory Sledgehammer
-imports Plain Hilbert_Choice
+imports Plain
 uses
   ("Tools/ATP/atp_problem.ML")
   ("Tools/ATP/atp_proof.ML")
   ("Tools/ATP/atp_systems.ML")
-  ("~~/src/Tools/Metis/metis.ML")
-  ("Tools/Sledgehammer/metis_translate.ML")
-  ("Tools/Sledgehammer/metis_reconstruct.ML")
-  ("Tools/Sledgehammer/metis_tactics.ML")
   ("Tools/Sledgehammer/sledgehammer_util.ML")
   ("Tools/Sledgehammer/sledgehammer_filter.ML")
   ("Tools/Sledgehammer/sledgehammer_translate.ML")
@@ -26,88 +22,11 @@
   ("Tools/Sledgehammer/sledgehammer_isar.ML")
 begin
 
-lemma TruepropI: "P \<equiv> Q \<Longrightarrow> Trueprop P \<equiv> Trueprop Q"
-by simp
-
-definition skolem :: "'a \<Rightarrow> 'a" where
-[no_atp]: "skolem = (\<lambda>x. x)"
-
-definition COMBI :: "'a \<Rightarrow> 'a" where
-[no_atp]: "COMBI P = P"
-
-definition COMBK :: "'a \<Rightarrow> 'b \<Rightarrow> 'a" where
-[no_atp]: "COMBK P Q = P"
-
-definition COMBB :: "('b => 'c) \<Rightarrow> ('a => 'b) \<Rightarrow> 'a \<Rightarrow> 'c" where [no_atp]:
-"COMBB P Q R = P (Q R)"
-
-definition COMBC :: "('a \<Rightarrow> 'b \<Rightarrow> 'c) \<Rightarrow> 'b \<Rightarrow> 'a \<Rightarrow> 'c" where
-[no_atp]: "COMBC P Q R = P R Q"
-
-definition COMBS :: "('a \<Rightarrow> 'b \<Rightarrow> 'c) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'c" where
-[no_atp]: "COMBS P Q R = P R (Q R)"
-
-definition fequal :: "'a \<Rightarrow> 'a \<Rightarrow> bool" where [no_atp]:
-"fequal X Y \<longleftrightarrow> (X = Y)"
-
-lemma fequal_imp_equal [no_atp]: "\<not> fequal X Y \<or> X = Y"
-by (simp add: fequal_def)
-
-lemma equal_imp_fequal [no_atp]: "\<not> X = Y \<or> fequal X Y"
-by (simp add: fequal_def)
-
-lemma equal_imp_equal [no_atp]: "X = Y ==> X = Y"
-by auto
-
-lemma skolem_COMBK_iff: "P \<longleftrightarrow> skolem (COMBK P (i\<Colon>nat))"
-unfolding skolem_def COMBK_def by (rule refl)
-
-lemmas skolem_COMBK_I = iffD1 [OF skolem_COMBK_iff]
-lemmas skolem_COMBK_D = iffD2 [OF skolem_COMBK_iff]
-
-text{*Theorems for translation to combinators*}
-
-lemma abs_S [no_atp]: "\<lambda>x. (f x) (g x) \<equiv> COMBS f g"
-apply (rule eq_reflection)
-apply (rule ext) 
-apply (simp add: COMBS_def) 
-done
-
-lemma abs_I [no_atp]: "\<lambda>x. x \<equiv> COMBI"
-apply (rule eq_reflection)
-apply (rule ext) 
-apply (simp add: COMBI_def) 
-done
-
-lemma abs_K [no_atp]: "\<lambda>x. y \<equiv> COMBK y"
-apply (rule eq_reflection)
-apply (rule ext) 
-apply (simp add: COMBK_def) 
-done
-
-lemma abs_B [no_atp]: "\<lambda>x. a (g x) \<equiv> COMBB a g"
-apply (rule eq_reflection)
-apply (rule ext) 
-apply (simp add: COMBB_def) 
-done
-
-lemma abs_C [no_atp]: "\<lambda>x. (f x) b \<equiv> COMBC f b"
-apply (rule eq_reflection)
-apply (rule ext) 
-apply (simp add: COMBC_def) 
-done
-
 use "Tools/ATP/atp_problem.ML"
 use "Tools/ATP/atp_proof.ML"
 use "Tools/ATP/atp_systems.ML"
 setup ATP_Systems.setup
 
-use "~~/src/Tools/Metis/metis.ML"
-use "Tools/Sledgehammer/metis_translate.ML"
-use "Tools/Sledgehammer/metis_reconstruct.ML"
-use "Tools/Sledgehammer/metis_tactics.ML"
-setup Metis_Tactics.setup
-
 use "Tools/Sledgehammer/sledgehammer_util.ML"
 use "Tools/Sledgehammer/sledgehammer_filter.ML"
 use "Tools/Sledgehammer/sledgehammer_translate.ML"
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/Metis/metis_reconstruct.ML	Mon Oct 04 22:45:09 2010 +0200
@@ -0,0 +1,557 @@
+(*  Title:      HOL/Tools/Sledgehammer/metis_reconstruct.ML
+    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
+    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
+    Author:     Jasmin Blanchette, TU Muenchen
+    Copyright   Cambridge University 2007
+
+Proof reconstruction for Metis.
+*)
+
+signature METIS_RECONSTRUCT =
+sig
+  type mode = Metis_Translate.mode
+
+  val trace : bool Unsynchronized.ref
+  val lookth : (Metis_Thm.thm * 'a) list -> Metis_Thm.thm -> 'a
+  val untyped_aconv : term -> term -> bool
+  val replay_one_inference :
+    Proof.context -> mode -> (string * term) list
+    -> Metis_Thm.thm * Metis_Proof.inference -> (Metis_Thm.thm * thm) list
+    -> (Metis_Thm.thm * thm) list
+end;
+
+structure Metis_Reconstruct : METIS_RECONSTRUCT =
+struct
+
+open Metis_Translate
+
+val trace = Unsynchronized.ref false
+fun trace_msg msg = if !trace then tracing (msg ()) else ()
+
+datatype term_or_type = SomeTerm of term | SomeType of typ
+
+fun terms_of [] = []
+  | terms_of (SomeTerm t :: tts) = t :: terms_of tts
+  | terms_of (SomeType _ :: tts) = terms_of tts;
+
+fun types_of [] = []
+  | types_of (SomeTerm (Var ((a,idx), _)) :: 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 (SomeTerm _ :: tts) = types_of tts
+  | types_of (SomeType T :: tts) = T :: types_of tts;
+
+fun apply_list rator nargs rands =
+  let val trands = terms_of rands
+  in  if length trands = nargs then SomeTerm (list_comb(rator, trands))
+      else raise Fail
+        ("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) = Var ((w, 1), T)
+
+(*include the default sort, if available*)
+fun mk_tfree ctxt w =
+  let val ww = "'" ^ w
+  in  TFree(ww, the_default HOLogic.typeS (Variable.def_sort ctxt (ww, ~1)))  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);
+
+fun make_tvar s = TVar (("'" ^ s, 0), HOLogic.typeS)
+
+fun smart_invert_const "fequal" = @{const_name HOL.eq}
+  | smart_invert_const s = invert_const s
+
+fun hol_type_from_metis_term _ (Metis_Term.Var v) =
+     (case strip_prefix_and_unascii tvar_prefix v of
+          SOME w => make_tvar w
+        | NONE   => make_tvar v)
+  | hol_type_from_metis_term ctxt (Metis_Term.Fn(x, tys)) =
+     (case strip_prefix_and_unascii type_const_prefix x of
+          SOME tc => Type (smart_invert_const tc,
+                           map (hol_type_from_metis_term ctxt) tys)
+        | NONE    =>
+      case strip_prefix_and_unascii tfree_prefix x of
+          SOME tf => mk_tfree ctxt tf
+        | NONE    => raise Fail ("hol_type_from_metis_term: " ^ x));
+
+(*Maps metis terms to isabelle terms*)
+fun hol_term_from_metis_PT ctxt fol_tm =
+  let val thy = ProofContext.theory_of ctxt
+      val _ = trace_msg (fn () => "hol_term_from_metis_PT: " ^
+                                  Metis_Term.toString fol_tm)
+      fun tm_to_tt (Metis_Term.Var v) =
+             (case strip_prefix_and_unascii tvar_prefix v of
+                  SOME w => SomeType (make_tvar w)
+                | NONE =>
+              case strip_prefix_and_unascii schematic_var_prefix v of
+                  SOME w => SomeTerm (mk_var (w, HOLogic.typeT))
+                | NONE   => SomeTerm (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
+                             SomeTerm t => SomeTerm (list_comb(t, terms_of (map tm_to_tt rands)))
+                           | _ => raise Fail "tm_to_tt: HO application"
+            end
+        | tm_to_tt (Metis_Term.Fn (fname, args)) = applic_to_tt (fname,args)
+      and applic_to_tt ("=",ts) =
+            SomeTerm (list_comb(Const (@{const_name HOL.eq}, HOLogic.typeT), terms_of (map tm_to_tt ts)))
+        | applic_to_tt (a,ts) =
+            case strip_prefix_and_unascii const_prefix a of
+                SOME b =>
+                  let
+                    val c = smart_invert_const b
+                    val ntypes = num_type_args thy c
+                    val nterms = length ts - ntypes
+                    val tts = map tm_to_tt ts
+                    val tys = types_of (List.take(tts,ntypes))
+                    val t =
+                      if String.isPrefix new_skolem_const_prefix c then
+                        Var (new_skolem_var_from_const c,
+                             Type_Infer.paramify_vars (tl tys ---> hd tys))
+                      else
+                        Const (c, dummyT)
+                  in if length tys = ntypes then
+                         apply_list t nterms (List.drop(tts,ntypes))
+                     else
+                       raise Fail ("Constant " ^ c ^ " expects " ^ Int.toString ntypes ^
+                                   " 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 strip_prefix_and_unascii type_const_prefix a of
+                SOME b =>
+                SomeType (Type (smart_invert_const b, types_of (map tm_to_tt ts)))
+              | NONE => (*Maybe a TFree. Should then check that ts=[].*)
+            case strip_prefix_and_unascii tfree_prefix a of
+                SOME b => SomeType (mk_tfree ctxt b)
+              | NONE => (*a fixed variable? They are Skolem functions.*)
+            case strip_prefix_and_unascii fixed_var_prefix a of
+                SOME b =>
+                  let val opr = Free (b, HOLogic.typeT)
+                  in  apply_list opr (length ts) (map tm_to_tt ts)  end
+              | NONE => raise Fail ("unexpected metis function: " ^ a)
+  in
+    case tm_to_tt fol_tm of
+      SomeTerm t => t
+    | SomeType T => raise TYPE ("fol_tm_to_tt: Term expected", [T], [])
+  end
+
+(*Maps fully-typed metis terms to isabelle terms*)
+fun hol_term_from_metis_FT ctxt fol_tm =
+  let val _ = trace_msg (fn () => "hol_term_from_metis_FT: " ^
+                                  Metis_Term.toString fol_tm)
+      fun cvt (Metis_Term.Fn ("ti", [Metis_Term.Var v, _])) =
+             (case strip_prefix_and_unascii schematic_var_prefix v of
+                  SOME w =>  mk_var(w, dummyT)
+                | NONE   => mk_var(v, dummyT))
+        | cvt (Metis_Term.Fn ("ti", [Metis_Term.Fn ("=",[]), _])) =
+            Const (@{const_name HOL.eq}, HOLogic.typeT)
+        | cvt (Metis_Term.Fn ("ti", [Metis_Term.Fn (x,[]), ty])) =
+           (case strip_prefix_and_unascii const_prefix x of
+                SOME c => Const (smart_invert_const c, dummyT)
+              | NONE => (*Not a constant. Is it a fixed variable??*)
+            case strip_prefix_and_unascii fixed_var_prefix x of
+                SOME v => Free (v, hol_type_from_metis_term ctxt ty)
+              | NONE => raise Fail ("hol_term_from_metis_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 (@{const_name HOL.eq}, HOLogic.typeT), map cvt [tm1,tm2])
+        | cvt (t as Metis_Term.Fn (x, [])) =
+           (case strip_prefix_and_unascii const_prefix x of
+                SOME c => Const (smart_invert_const c, dummyT)
+              | NONE => (*Not a constant. Is it a fixed variable??*)
+            case strip_prefix_and_unascii fixed_var_prefix x of
+                SOME v => Free (v, dummyT)
+              | NONE => (trace_msg (fn () => "hol_term_from_metis_FT bad const: " ^ x);
+                  hol_term_from_metis_PT ctxt t))
+        | cvt t = (trace_msg (fn () => "hol_term_from_metis_FT bad term: " ^ Metis_Term.toString t);
+            hol_term_from_metis_PT ctxt t)
+  in fol_tm |> cvt end
+
+fun hol_term_from_metis FT = hol_term_from_metis_FT
+  | hol_term_from_metis _ = hol_term_from_metis_PT
+
+fun hol_terms_from_fol ctxt mode old_skolems fol_tms =
+  let val ts = map (hol_term_from_metis mode ctxt) 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' = ts |> map (reveal_old_skolem_terms old_skolems)
+                   |> infer_types ctxt
+      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;
+
+(* ------------------------------------------------------------------------- *)
+(* 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));
+*)
+
+fun lookth thpairs (fth : Metis_Thm.thm) =
+  the (AList.lookup (uncurry Metis_Thm.equal) thpairs fth)
+  handle Option.Option =>
+         raise Fail ("Failed to find Metis theorem " ^ Metis_Thm.toString fth)
+
+fun cterm_incr_types thy idx = cterm_of thy o (map_types (Logic.incr_tvar idx));
+
+(* INFERENCE RULE: AXIOM *)
+
+fun axiom_inf thpairs th = Thm.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 *)
+
+val EXCLUDED_MIDDLE = @{lemma "P ==> ~ P ==> False" by (rule notE)}
+
+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 assume_inf ctxt mode old_skolems atm =
+  inst_excluded_middle
+      (ProofContext.theory_of ctxt)
+      (singleton (hol_terms_from_fol ctxt mode old_skolems) (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 old_skolems 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 = the (List.find (fn ((a,_),_) => a=x) i_th_vars)
+      fun subst_translation (x,y) =
+        let val v = find_var x
+            (* We call "reveal_old_skolem_terms" and "infer_types" below. *)
+            val t = hol_term_from_metis mode ctxt y
+        in  SOME (cterm_of thy (Var v), t)  end
+        handle Option.Option =>
+               (trace_msg (fn () => "\"find_var\" failed for " ^ x ^
+                                    " in " ^ Display.string_of_thm ctxt i_th);
+                NONE)
+             | TYPE _ =>
+               (trace_msg (fn () => "\"hol_term_from_metis\" failed for " ^ x ^
+                                    " in " ^ Display.string_of_thm ctxt i_th);
+                NONE)
+      fun remove_typeinst (a, t) =
+            case strip_prefix_and_unascii schematic_var_prefix a of
+                SOME b => SOME (b, t)
+              | NONE => case strip_prefix_and_unascii 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 = rawtms |> map (reveal_old_skolem_terms old_skolems)
+                       |> infer_types ctxt
+      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 end
+  handle THM (msg, _, _) =>
+         error ("Cannot replay Metis proof in Isabelle:\n" ^ msg)
+
+(* 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 thy tha i thb =
+  let
+    val tha = Drule.incr_type_indexes (1 + Thm.maxidx_of thb) tha
+    fun aux tha thb =
+      case Thm.bicompose false (false, tha, nprems_of tha) i thb
+           |> Seq.list_of |> distinct Thm.eq_thm of
+        [th] => th
+      | _ => raise THM ("resolve_inc_tyvars: unique result expected", i,
+                        [tha, thb])
+  in
+    aux tha thb
+    handle TERM z =>
+           (* The unifier, which is invoked from "Thm.bicompose", will sometimes
+              refuse to unify "?a::?'a" with "?a::?'b" or "?a::nat" and throw a
+              "TERM" exception (with "add_ffpair" as first argument). We then
+              perform unification of the types of variables by hand and try
+              again. We could do this the first time around but this error
+              occurs seldom and we don't want to break existing proofs in subtle
+              ways or slow them down needlessly. *)
+           case [] |> fold (Term.add_vars o prop_of) [tha, thb]
+                   |> AList.group (op =)
+                   |> maps (fn ((s, _), T :: Ts) =>
+                               map (fn T' => (Free (s, T), Free (s, T'))) Ts)
+                   |> rpair (Envir.empty ~1)
+                   |-> fold (Pattern.unify thy)
+                   |> Envir.type_env |> Vartab.dest
+                   |> map (fn (x, (S, T)) =>
+                              pairself (ctyp_of thy) (TVar (x, S), T)) of
+             [] => raise TERM z
+           | ps => aux (instantiate (ps, []) tha) (instantiate (ps, []) thb)
+  end
+
+fun mk_not (Const (@{const_name Not}, _) $ b) = b
+  | mk_not b = HOLogic.mk_not b
+
+(* 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, for some reason. *)
+  | untyped_aconv (Bound i) (Bound j) = (i = j)
+  | untyped_aconv (Abs (_, _, t)) (Abs (_, _, u)) = 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 literal_index lit =
+  let
+    val lit = Envir.eta_contract lit
+    fun get _ [] = 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
+
+(* Permute a rule's premises to move the i-th premise to the last position. *)
+fun make_last i th =
+  let val n = nprems_of th
+  in  if 1 <= i andalso i <= n
+      then Thm.permute_prems (i-1) 1 th
+      else raise THM("select_literal", i, [th])
+  end;
+
+(* Maps a rule that ends "... ==> P ==> False" to "... ==> ~P" while suppressing
+   double-negations. *)
+val negate_head = rewrite_rule [@{thm atomize_not}, not_not RS eq_reflection]
+
+(* Maps the clause  [P1,...Pn]==>False to [P1,...,P(i-1),P(i+1),...Pn] ==> ~P *)
+val select_literal = negate_head oo make_last
+
+fun resolve_inf ctxt mode old_skolems 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
+    (* Trivial cases where one operand is type info *)
+    if Thm.eq_thm (TrueI, i_th1) then
+      i_th2
+    else if Thm.eq_thm (TrueI, i_th2) then
+      i_th1
+    else
+      let
+        val i_atm = singleton (hol_terms_from_fol ctxt mode old_skolems)
+                              (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 = literal_index (mk_not i_atm) prems_th1
+              handle Empty => raise Fail "Failed to find literal in th1"
+        val _ = trace_msg (fn () => "  index_th1: " ^ Int.toString index_th1)
+        val index_th2 = literal_index i_atm prems_th2
+              handle Empty => raise Fail "Failed to find literal in th2"
+        val _ = trace_msg (fn () => "  index_th2: " ^ Int.toString index_th2)
+    in
+      resolve_inc_tyvars thy (select_literal index_th1 i_th1) index_th2 i_th2
+    end
+  end;
+
+(* INFERENCE RULE: REFL *)
+
+val REFL_THM = Thm.incr_indexes 2 @{lemma "t ~= t ==> False" by simp}
+
+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 old_skolems t =
+  let val thy = ProofContext.theory_of ctxt
+      val i_t = singleton (hol_terms_from_fol ctxt mode old_skolems) 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;
+
+(* INFERENCE RULE: EQUALITY *)
+
+val subst_em = @{lemma "s = t ==> P s ==> ~ P t ==> False" by simp}
+val ssubst_em = @{lemma "s = t ==> P t ==> ~ P s ==> False" by simp}
+
+val metis_eq = Metis_Term.Fn ("=", []);
+
+fun get_ty_arg_size _ (Const (@{const_name HOL.eq}, _)) = 0  (*equality has no type arguments*)
+  | get_ty_arg_size thy (Const (c, _)) = (num_type_args thy c handle TYPE _ => 0)
+  | get_ty_arg_size _ _ = 0;
+
+fun equality_inf ctxt mode old_skolems (pos, atm) fp fr =
+  let val thy = ProofContext.theory_of ctxt
+      val m_tm = Metis_Term.Fn atm
+      val [i_atm,i_tm] = hol_terms_from_fol ctxt mode old_skolems [m_tm, fr]
+      val _ = trace_msg (fn () => "sign of the literal: " ^ Bool.toString pos)
+      fun replace_item_list lx 0 (_::ls) = lx::ls
+        | replace_item_list lx i (l::ls) = l :: replace_item_list lx (i-1) ls
+      fun path_finder_FO tm [] = (tm, Bound 0)
+        | path_finder_FO tm (p::ps) =
+            let val (tm1,args) = 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 ("Cannot replay Metis proof in Isabelle:\n" ^
+                                "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, Bound 0)
+        | path_finder_HO (t$u) (0::ps) = (fn(x,y) => (x, y$u)) (path_finder_HO t ps)
+        | path_finder_HO (t$u) (_::ps) = (fn(x,y) => (x, t$y)) (path_finder_HO u ps)
+        | path_finder_HO tm ps =
+          raise Fail ("Cannot replay Metis proof in Isabelle:\n" ^
+                      "equality_inf, path_finder_HO: path = " ^
+                      space_implode " " (map Int.toString ps) ^
+                      " isa-term: " ^  Syntax.string_of_term ctxt tm)
+      fun path_finder_FT tm [] _ = (tm, Bound 0)
+        | path_finder_FT tm (0::ps) (Metis_Term.Fn ("ti", [t1, _])) =
+            path_finder_FT tm ps t1
+        | path_finder_FT (t$u) (0::ps) (Metis_Term.Fn (".", [t1, _])) =
+            (fn(x,y) => (x, y$u)) (path_finder_FT t ps t1)
+        | path_finder_FT (t$u) (1::ps) (Metis_Term.Fn (".", [_, t2])) =
+            (fn(x,y) => (x, t$y)) (path_finder_FT u ps t2)
+        | path_finder_FT tm ps t =
+          raise Fail ("Cannot replay Metis proof in Isabelle:\n" ^
+                      "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(@{const_name HOL.eq},_) $ _ $ _) (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 (_ :: ps) (Metis_Term.Fn ("{}", [_])) =
+             path_finder_HO tm ps      (*if not equality, ignore head to skip hBOOL*)
+        | path_finder FT (tm as Const(@{const_name HOL.eq}, _) $ _ $ _) (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 (_ :: 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 Const (@{const_name 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 = Abs ("x", 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' = Thm.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;
+
+fun step ctxt mode old_skolems thpairs p =
+  case p of
+    (fol_th, Metis_Proof.Axiom _) => factor (axiom_inf thpairs fol_th)
+  | (_, Metis_Proof.Assume f_atm) => assume_inf ctxt mode old_skolems f_atm
+  | (_, Metis_Proof.Metis_Subst (f_subst, f_th1)) =>
+    factor (inst_inf ctxt mode old_skolems thpairs f_subst f_th1)
+  | (_, Metis_Proof.Resolve(f_atm, f_th1, f_th2)) =>
+    factor (resolve_inf ctxt mode old_skolems thpairs f_atm f_th1 f_th2)
+  | (_, Metis_Proof.Refl f_tm) => refl_inf ctxt mode old_skolems f_tm
+  | (_, Metis_Proof.Equality (f_lit, f_p, f_r)) =>
+    equality_inf ctxt mode old_skolems f_lit f_p f_r
+
+fun flexflex_first_order th =
+  case Thm.tpairs_of th of
+      [] => th
+    | pairs =>
+        let val thy = theory_of_thm th
+            val (_, tenv) =
+              fold (Pattern.first_order_match thy) pairs (Vartab.empty, Vartab.empty)
+            val t_pairs = map Meson.term_pair_of (Vartab.dest tenv)
+            val th' = Thm.instantiate ([], map (pairself (cterm_of thy)) t_pairs) th
+        in  th'  end
+        handle THM _ => th;
+
+fun is_metis_literal_genuine (_, (s, _)) = not (String.isPrefix class_prefix s)
+fun is_isabelle_literal_genuine t =
+  case t of _ $ (Const (@{const_name skolem}, _) $ _) => false | _ => true
+
+fun count p xs = fold (fn x => if p x then Integer.add 1 else I) xs 0
+
+fun replay_one_inference ctxt mode old_skolems (fol_th, inf) thpairs =
+  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 = step ctxt mode old_skolems thpairs (fol_th, inf)
+             |> flexflex_first_order
+    val _ = trace_msg (fn () => "ISABELLE THM: " ^ Display.string_of_thm ctxt th)
+    val _ = trace_msg (fn () => "=============================================")
+    val num_metis_lits =
+      fol_th |> Metis_Thm.clause |> Metis_LiteralSet.toList
+             |> count is_metis_literal_genuine
+    val num_isabelle_lits =
+      th |> prems_of |> count is_isabelle_literal_genuine
+    val _ = if num_metis_lits = num_isabelle_lits then ()
+            else error "Cannot replay Metis proof in Isabelle: Out of sync."
+  in (fol_th, th) :: thpairs end
+
+end;
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/Metis/metis_tactics.ML	Mon Oct 04 22:45:09 2010 +0200
@@ -0,0 +1,449 @@
+(*  Title:      HOL/Tools/Sledgehammer/metis_tactics.ML
+    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
+    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
+    Author:     Jasmin Blanchette, TU Muenchen
+    Copyright   Cambridge University 2007
+
+HOL setup for the Metis prover.
+*)
+
+signature METIS_TACTICS =
+sig
+  val trace : bool Unsynchronized.ref
+  val type_lits : bool Config.T
+  val new_skolemizer : bool Config.T
+  val metis_tac : Proof.context -> thm list -> int -> tactic
+  val metisF_tac : Proof.context -> thm list -> int -> tactic
+  val metisFT_tac : Proof.context -> thm list -> int -> tactic
+  val setup : theory -> theory
+end
+
+structure Metis_Tactics : METIS_TACTICS =
+struct
+
+open Metis_Translate
+open Metis_Reconstruct
+
+structure Int_Pair_Graph =
+  Graph(type key = int * int val ord = prod_ord int_ord int_ord)
+
+fun trace_msg msg = if !trace then tracing (msg ()) else ()
+
+val (type_lits, type_lits_setup) = Attrib.config_bool "metis_type_lits" (K true)
+val (new_skolemizer, new_skolemizer_setup) =
+  Attrib.config_bool "metis_new_skolemizer" (K false)
+
+fun is_false t = t aconv (HOLogic.mk_Trueprop HOLogic.false_const);
+
+fun have_common_thm ths1 ths2 =
+  exists (member Thm.eq_thm ths1) (map Meson.make_meta_clause ths2)
+
+(*Determining which axiom clauses are actually used*)
+fun used_axioms axioms (th, Metis_Proof.Axiom _) = SOME (lookth axioms th)
+  | used_axioms _ _ = NONE;
+
+val clause_params =
+  {ordering = Metis_KnuthBendixOrder.default,
+   orderLiterals = Metis_Clause.UnsignedLiteralOrder,
+   orderTerms = true}
+val active_params =
+  {clause = clause_params,
+   prefactor = #prefactor Metis_Active.default,
+   postfactor = #postfactor Metis_Active.default}
+val waiting_params =
+  {symbolsWeight = 1.0,
+   variablesWeight = 0.0,
+   literalsWeight = 0.0,
+   models = []}
+val resolution_params = {active = active_params, waiting = waiting_params}
+
+fun instantiate_theorem thy inst th =
+  let
+    val tyenv = Vartab.empty |> fold (Type.raw_unify o pairself fastype_of) inst
+    val instT =
+      [] |> Vartab.fold (fn (z, (S, T)) =>
+                            cons (TVar (z, S), Type.devar tyenv T)) tyenv
+    val inst = inst |> map (pairself (subst_atomic_types instT))
+    val _ = tracing (cat_lines (map (fn (T, U) =>
+        Syntax.string_of_typ @{context} T ^ " |-> " ^
+        Syntax.string_of_typ @{context} U) instT))
+    val _ = tracing (cat_lines (map (fn (t, u) =>
+        Syntax.string_of_term @{context} t ^ " |-> " ^
+        Syntax.string_of_term @{context} u) inst))
+    val cinstT = instT |> map (pairself (ctyp_of thy))
+    val cinst = inst |> map (pairself (cterm_of thy))
+  in th |> Thm.instantiate (cinstT, cinst) end
+
+(* In principle, it should be sufficient to apply "assume_tac" to unify the
+   conclusion with one of the premises. However, in practice, this is unreliable
+   because of the mildly higher-order nature of the unification problems.
+   Typical constraints are of the form
+   "?SK_a_b_c_x SK_d_e_f_y ... SK_a_b_c_x ... SK_g_h_i_z =?= SK_a_b_c_x",
+   where the nonvariables are goal parameters. *)
+fun unify_first_prem_with_concl thy i th =
+  let
+    val goal = Logic.get_goal (prop_of th) i |> Envir.beta_eta_contract
+    val prem = goal |> Logic.strip_assums_hyp |> hd
+    val concl = goal |> Logic.strip_assums_concl
+    fun pair_untyped_aconv (t1, t2) (u1, u2) =
+      untyped_aconv t1 u1 andalso untyped_aconv t2 u2
+    fun add_terms tp inst =
+      if exists (pair_untyped_aconv tp) inst then inst
+      else tp :: map (apsnd (subst_atomic [tp])) inst
+    fun is_flex t =
+      case strip_comb t of
+        (Var _, args) => forall is_Bound args
+      | _ => false
+    fun unify_flex flex rigid =
+      case strip_comb flex of
+        (Var (z as (_, T)), args) =>
+        add_terms (Var z,
+          fold_rev (curry absdummy) (take (length args) (binder_types T)) rigid)
+      | _ => raise TERM ("unify_flex: expected flex", [flex])
+    fun unify_potential_flex comb atom =
+      if is_flex comb then unify_flex comb atom
+      else if is_Var atom then add_terms (atom, comb)
+      else raise TERM ("unify_terms", [comb, atom])
+    fun unify_terms (t, u) =
+      case (t, u) of
+        (t1 $ t2, u1 $ u2) =>
+        if is_flex t then unify_flex t u
+        else if is_flex u then unify_flex u t
+        else fold unify_terms [(t1, u1), (t2, u2)]
+      | (_ $ _, _) => unify_potential_flex t u
+      | (_, _ $ _) => unify_potential_flex u t
+      | (Var _, _) => add_terms (t, u)
+      | (_, Var _) => add_terms (u, t)
+      | _ => if untyped_aconv t u then I else raise TERM ("unify_terms", [t, u])
+  in th |> instantiate_theorem thy (unify_terms (prem, concl) []) end
+
+fun shuffle_key (((axiom_no, (_, index_no)), _), _) = (index_no, axiom_no)
+fun shuffle_ord p =
+  rev_order (prod_ord int_ord int_ord (pairself shuffle_key p))
+
+val copy_prem = @{lemma "P ==> (P ==> P ==> Q) ==> Q" by fast}
+
+fun copy_prems_tac [] ns i =
+    if forall (curry (op =) 1) ns then all_tac else copy_prems_tac (rev ns) [] i
+  | copy_prems_tac (1 :: ms) ns i =
+    rotate_tac 1 i THEN copy_prems_tac ms (1 :: ns) i
+  | copy_prems_tac (m :: ms) ns i =
+    etac copy_prem i THEN copy_prems_tac ms (m div 2 :: (m + 1) div 2 :: ns) i
+
+fun instantiate_forall_tac thy params t i =
+  let
+    fun repair (t as (Var ((s, _), _))) =
+        (case find_index (fn ((s', _), _) => s' = s) params of
+           ~1 => t
+         | j => Bound j)
+      | repair (t $ u) = repair t $ repair u
+      | repair t = t
+    val t' = t |> repair |> fold (curry absdummy) (map snd params)
+    fun do_instantiate th =
+      let val var = Term.add_vars (prop_of th) [] |> the_single in
+        th |> instantiate_theorem thy [(Var var, t')]
+      end
+  in
+    etac @{thm allE} i
+    THEN rotate_tac ~1 i
+    THEN PRIMITIVE do_instantiate
+  end
+
+fun release_clusters_tac _ _ _ _ [] = K all_tac
+  | release_clusters_tac thy ax_counts substs params
+                         ((ax_no, cluster_no) :: clusters) =
+    let
+      fun in_right_cluster s =
+        (s |> Meson_Clausify.cluster_of_zapped_var_name |> fst |> snd |> fst)
+        = cluster_no
+      val cluster_substs =
+        substs
+        |> map_filter (fn (ax_no', (_, (_, tsubst))) =>
+                          if ax_no' = ax_no then
+                            tsubst |> filter (in_right_cluster
+                                               o fst o fst o dest_Var o fst)
+                                    |> map snd |> SOME
+                           else
+                             NONE)
+      val n = length cluster_substs
+      fun do_cluster_subst cluster_subst =
+        map (instantiate_forall_tac thy params) cluster_subst @ [rotate_tac 1]
+      val params' = params (* FIXME ### existentials! *)
+      val first_prem = find_index (fn (ax_no', _) => ax_no' = ax_no) substs
+    in
+      rotate_tac first_prem
+      THEN' (EVERY' (maps do_cluster_subst cluster_substs))
+      THEN' rotate_tac (~ first_prem - length cluster_substs)
+      THEN' release_clusters_tac thy ax_counts substs params' clusters
+    end
+
+val cluster_ord =
+  prod_ord (prod_ord int_ord (prod_ord int_ord int_ord)) bool_ord
+
+val tysubst_ord =
+  list_ord (prod_ord Term_Ord.fast_indexname_ord
+                     (prod_ord Term_Ord.sort_ord Term_Ord.typ_ord))
+
+structure Int_Tysubst_Table =
+  Table(type key = int * (indexname * (sort * typ)) list
+        val ord = prod_ord int_ord tysubst_ord)
+
+(* Attempts to derive the theorem "False" from a theorem of the form
+   "P1 ==> ... ==> Pn ==> False", where the "Pi"s are to be discharged using the
+   specified axioms. The axioms have leading "All" and "Ex" quantifiers, which
+   must be eliminated first. *)
+fun discharge_skolem_premises ctxt axioms prems_imp_false =
+  if prop_of prems_imp_false aconv @{prop False} then
+    prems_imp_false
+  else
+    let
+      val thy = ProofContext.theory_of ctxt
+      (* distinguish variables with same name but different types *)
+      val prems_imp_false' =
+        prems_imp_false |> try (forall_intr_vars #> gen_all)
+                        |> the_default prems_imp_false
+      val prems_imp_false =
+        if prop_of prems_imp_false aconv prop_of prems_imp_false' then
+          prems_imp_false
+        else
+          prems_imp_false'
+      fun match_term p =
+        let
+          val (tyenv, tenv) =
+            Pattern.first_order_match thy p (Vartab.empty, Vartab.empty)
+          val tsubst =
+            tenv |> Vartab.dest
+                 |> sort (cluster_ord
+                          o pairself (Meson_Clausify.cluster_of_zapped_var_name
+                                      o fst o fst))
+                 |> map (Meson.term_pair_of
+                         #> pairself (Envir.subst_term_types tyenv))
+          val tysubst = tyenv |> Vartab.dest
+        in (tysubst, tsubst) end
+      fun subst_info_for_prem subgoal_no prem =
+        case prem of
+          _ $ (Const (@{const_name skolem}, _) $ (_ $ t $ num)) =>
+          let val ax_no = HOLogic.dest_nat num in
+            (ax_no, (subgoal_no,
+                     match_term (nth axioms ax_no |> the |> snd, t)))
+          end
+        | _ => raise TERM ("discharge_skolem_premises: Malformed premise",
+                           [prem])
+      fun cluster_of_var_name skolem s =
+        let
+          val ((ax_no, (cluster_no, _)), skolem') =
+            Meson_Clausify.cluster_of_zapped_var_name s
+        in
+          if skolem' = skolem andalso cluster_no > 0 then
+            SOME (ax_no, cluster_no)
+          else
+            NONE
+        end
+      fun clusters_in_term skolem t =
+        Term.add_var_names t [] |> map_filter (cluster_of_var_name skolem o fst)
+      fun deps_for_term_subst (var, t) =
+        case clusters_in_term false var of
+          [] => NONE
+        | [(ax_no, cluster_no)] =>
+          SOME ((ax_no, cluster_no),
+                clusters_in_term true t
+                |> cluster_no > 1 ? cons (ax_no, cluster_no - 1))
+        | _ => raise TERM ("discharge_skolem_premises: Expected Var", [var])
+      val prems = Logic.strip_imp_prems (prop_of prems_imp_false)
+      val substs = prems |> map2 subst_info_for_prem (1 upto length prems)
+                         |> sort (int_ord o pairself fst)
+      val depss = maps (map_filter deps_for_term_subst o snd o snd o snd) substs
+      val clusters = maps (op ::) depss
+      val ordered_clusters =
+        Int_Pair_Graph.empty
+        |> fold Int_Pair_Graph.default_node (map (rpair ()) clusters)
+        |> fold Int_Pair_Graph.add_deps_acyclic depss
+        |> Int_Pair_Graph.topological_order
+        handle Int_Pair_Graph.CYCLES _ =>
+               error "Cannot replay Metis proof in Isabelle without axiom of \
+                     \choice."
+      val params0 =
+        [] |> fold (Term.add_vars o snd) (map_filter I axioms)
+           |> map (`(Meson_Clausify.cluster_of_zapped_var_name o fst o fst))
+           |> filter (fn (((_, (cluster_no, _)), skolem), _) =>
+                         cluster_no = 0 andalso skolem)
+           |> sort shuffle_ord |> map snd
+      val ax_counts =
+        Int_Tysubst_Table.empty
+        |> fold (fn (ax_no, (_, (tysubst, _))) =>
+                    Int_Tysubst_Table.map_default ((ax_no, tysubst), 0)
+                                                  (Integer.add 1)) substs
+        |> Int_Tysubst_Table.dest
+(* for debugging:
+      fun string_for_subst_info (ax_no, (subgoal_no, (tysubst, tsubst))) =
+        "ax: " ^ string_of_int ax_no ^ "; asm: " ^ string_of_int subgoal_no ^
+        "; tysubst: " ^ PolyML.makestring tysubst ^ "; tsubst: {" ^
+        commas (map ((fn (s, t) => s ^ " |-> " ^ t)
+                     o pairself (Syntax.string_of_term ctxt)) tsubst) ^ "}"
+      val _ = tracing ("SUBSTS (" ^ string_of_int (length substs) ^ "):\n" ^
+                       cat_lines (map string_for_subst_info substs))
+      val _ = tracing ("OUTERMOST SKOLEMS: " ^ PolyML.makestring params0)
+      val _ = tracing ("ORDERED CLUSTERS: " ^ PolyML.makestring ordered_clusters)
+      val _ = tracing ("AXIOM COUNTS: " ^ PolyML.makestring ax_counts)
+*)
+      fun rotation_for_subgoal i =
+        find_index (fn (_, (subgoal_no, _)) => subgoal_no = i) substs
+    in
+      Goal.prove ctxt [] [] @{prop False}
+          (K (cut_rules_tac
+                  (map (fst o the o nth axioms o fst o fst) ax_counts) 1
+              THEN print_tac "cut:"
+              THEN TRY (REPEAT_ALL_NEW (etac @{thm exE}) 1)
+              THEN copy_prems_tac (map snd ax_counts) [] 1
+              THEN print_tac "eliminated exist and copied prems:"
+              THEN release_clusters_tac thy ax_counts substs params0
+                                        ordered_clusters 1
+              THEN print_tac "released clusters:"
+              THEN match_tac [prems_imp_false] 1
+              THEN print_tac "applied rule:"
+              THEN ALLGOALS (fn i =>
+                       rtac @{thm skolem_COMBK_I} i
+                       THEN rotate_tac (rotation_for_subgoal i) i
+                       THEN PRIMITIVE (unify_first_prem_with_concl thy i)
+                       THEN assume_tac i)))
+    end
+
+(* Main function to start Metis proof and reconstruction *)
+fun FOL_SOLVE mode ctxt cls ths0 =
+  let val thy = ProofContext.theory_of ctxt
+      val type_lits = Config.get ctxt type_lits
+      val new_skolemizer =
+        Config.get ctxt new_skolemizer orelse null (Meson_Choices.get ctxt)
+      val th_cls_pairs =
+        map2 (fn j => fn th =>
+                (Thm.get_name_hint th,
+                 Meson_Clausify.cnf_axiom ctxt new_skolemizer j th))
+             (0 upto length ths0 - 1) ths0
+      val thss = map (snd o snd) th_cls_pairs
+      val dischargers = map (fst o snd) 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 (app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th))) thss
+      val (mode, {axioms, tfrees, old_skolems}) =
+        build_logic_map mode ctxt type_lits cls thss
+      val _ = if null tfrees then ()
+              else (trace_msg (fn () => "TFREE CLAUSES");
+                    app (fn TyLitFree ((s, _), (s', _)) =>
+                            trace_msg (fn () => s ^ "(" ^ s' ^ ")")) 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 filter (is_false o prop_of) cls of
+          false_th::_ => [false_th RS @{thm FalseE}]
+        | [] =>
+      case Metis_Resolution.new resolution_params {axioms = thms, conjecture = []}
+           |> Metis_Resolution.loop 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 =
+                  fold (replay_one_inference ctxt' mode old_skolems) proof axioms
+                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 = th_cls_pairs |> map_filter (fn (name, (_, cls)) =>
+                  if have_common_thm used cls then NONE else SOME name)
+            in
+                if not (null cls) andalso not (have_common_thm used cls) then
+                  warning "Metis: The assumptions are inconsistent."
+                else
+                  ();
+                if not (null unused) then
+                  warning ("Metis: Unused theorems: " ^ commas_quote unused
+                           ^ ".")
+                else
+                  ();
+                case result of
+                    (_,ith)::_ =>
+                        (trace_msg (fn () => "Success: " ^ Display.string_of_thm ctxt ith);
+                         [discharge_skolem_premises ctxt dischargers ith])
+                  | _ => (trace_msg (fn () => "Metis: No result"); [])
+            end
+        | Metis_Resolution.Satisfiable _ =>
+            (trace_msg (fn () => "Metis: No first-order proof with the lemmas supplied");
+             [])
+  end;
+
+(* Extensionalize "th", because that makes sense and that's what Sledgehammer
+   does, but also keep an unextensionalized version of "th" for backward
+   compatibility. *)
+fun also_extensionalize_theorem th =
+  let val th' = Meson_Clausify.extensionalize_theorem th in
+    if Thm.eq_thm (th, th') then [th]
+    else th :: Meson.make_clauses_unsorted [th']
+  end
+
+val neg_clausify =
+  single
+  #> Meson.make_clauses_unsorted
+  #> maps also_extensionalize_theorem
+  #> map Meson_Clausify.introduce_combinators_in_theorem
+  #> Meson.finish_cnf
+
+fun preskolem_tac ctxt st0 =
+  (if exists (Meson.has_too_many_clauses ctxt)
+             (Logic.prems_of_goal (prop_of st0) 1) then
+     cnf.cnfx_rewrite_tac ctxt 1
+   else
+     all_tac) st0
+
+val type_has_top_sort =
+  exists_subtype (fn TFree (_, []) => true | TVar (_, []) => true | _ => false)
+
+fun generic_metis_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 type_has_top_sort (prop_of st0) then
+      (warning ("Metis: Proof state contains the universal sort {}"); Seq.empty)
+    else
+      Meson.MESON (preskolem_tac ctxt) (maps neg_clausify)
+                  (fn cls => resolve_tac (FOL_SOLVE mode ctxt cls ths) 1)
+                  ctxt i st0
+  end
+
+val metis_tac = generic_metis_tac HO
+val metisF_tac = generic_metis_tac FO
+val metisFT_tac = generic_metis_tac FT
+
+(* Whenever "X" has schematic type variables, we treat "using X by metis" as
+   "by (metis X)", to prevent "Subgoal.FOCUS" from freezing the type variables.
+   We don't do it for nonschematic facts "X" because this breaks a few proofs
+   (in the rare and subtle case where a proof relied on extensionality not being
+   applied) and brings few benefits. *)
+val has_tvar =
+  exists_type (exists_subtype (fn TVar _ => true | _ => false)) o prop_of
+fun method name mode =
+  Method.setup name (Attrib.thms >> (fn ths => fn ctxt =>
+    METHOD (fn facts =>
+               let
+                 val (schem_facts, nonschem_facts) =
+                   List.partition has_tvar facts
+               in
+                 HEADGOAL (Method.insert_tac nonschem_facts THEN'
+                           CHANGED_PROP
+                           o generic_metis_tac mode ctxt (schem_facts @ ths))
+               end)))
+
+val setup =
+  type_lits_setup
+  #> new_skolemizer_setup
+  #> method @{binding metis} HO "Metis for FOL/HOL problems"
+  #> method @{binding metisF} FO "Metis for FOL problems"
+  #> method @{binding metisFT} FT
+            "Metis for FOL/HOL problems with fully-typed translation"
+
+end;
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/Metis/metis_translate.ML	Mon Oct 04 22:45:09 2010 +0200
@@ -0,0 +1,771 @@
+(*  Title:      HOL/Tools/Sledgehammer/metis_translate.ML
+    Author:     Jia Meng, Cambridge University Computer Laboratory and NICTA
+    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
+    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
+    Author:     Jasmin Blanchette, TU Muenchen
+
+Translation of HOL to FOL for Metis.
+*)
+
+signature METIS_TRANSLATE =
+sig
+  type name = string * string
+  datatype type_literal =
+    TyLitVar of name * name |
+    TyLitFree of name * name
+  datatype arLit =
+    TConsLit of name * name * name list |
+    TVarLit of name * name
+  datatype arity_clause =
+    ArityClause of {name: string, conclLit: arLit, premLits: arLit list}
+  datatype class_rel_clause =
+    ClassRelClause of {name: string, subclass: name, superclass: name}
+  datatype combtyp =
+    CombTVar of name |
+    CombTFree of name |
+    CombType of name * combtyp list
+  datatype combterm =
+    CombConst of name * combtyp * combtyp list (* Const and Free *) |
+    CombVar of name * combtyp |
+    CombApp of combterm * combterm
+  datatype fol_literal = FOLLiteral of bool * combterm
+
+  datatype mode = FO | HO | FT
+  type logic_map =
+    {axioms: (Metis_Thm.thm * thm) list,
+     tfrees: type_literal list,
+     old_skolems: (string * term) list}
+
+  val type_wrapper_name : string
+  val bound_var_prefix : string
+  val schematic_var_prefix: string
+  val fixed_var_prefix: string
+  val tvar_prefix: string
+  val tfree_prefix: string
+  val const_prefix: string
+  val type_const_prefix: string
+  val class_prefix: string
+  val new_skolem_const_prefix : string
+  val invert_const: string -> string
+  val ascii_of: string -> string
+  val unascii_of: string -> string
+  val strip_prefix_and_unascii: string -> string -> string option
+  val make_bound_var : string -> string
+  val make_schematic_var : string * int -> string
+  val make_fixed_var : string -> string
+  val make_schematic_type_var : string * int -> string
+  val make_fixed_type_var : string -> string
+  val make_fixed_const : string -> string
+  val make_fixed_type_const : string -> string
+  val make_type_class : string -> string
+  val num_type_args: theory -> string -> int
+  val new_skolem_var_from_const: string -> indexname
+  val type_literals_for_types : typ list -> type_literal list
+  val make_class_rel_clauses :
+    theory -> class list -> class list -> class_rel_clause list
+  val make_arity_clauses :
+    theory -> string list -> class list -> class list * arity_clause list
+  val combtyp_of : combterm -> combtyp
+  val strip_combterm_comb : combterm -> combterm * combterm list
+  val combterm_from_term :
+    theory -> int -> (string * typ) list -> term -> combterm * typ list
+  val reveal_old_skolem_terms : (string * term) list -> term -> term
+  val tfree_classes_of_terms : term list -> string list
+  val tvar_classes_of_terms : term list -> string list
+  val type_consts_of_terms : theory -> term list -> string list
+  val string_of_mode : mode -> string
+  val build_logic_map :
+    mode -> Proof.context -> bool -> thm list -> thm list list
+    -> mode * logic_map
+end
+
+structure Metis_Translate : METIS_TRANSLATE =
+struct
+
+val type_wrapper_name = "ti"
+
+val bound_var_prefix = "B_"
+val schematic_var_prefix = "V_"
+val fixed_var_prefix = "v_"
+
+val tvar_prefix = "T_";
+val tfree_prefix = "t_";
+
+val const_prefix = "c_";
+val type_const_prefix = "tc_";
+val class_prefix = "class_";
+
+val skolem_const_prefix = "Sledgehammer" ^ Long_Name.separator ^ "Sko"
+val old_skolem_const_prefix = skolem_const_prefix ^ "o"
+val new_skolem_const_prefix = skolem_const_prefix ^ "n"
+
+fun union_all xss = fold (union (op =)) xss []
+
+(* Readable names for the more common symbolic functions. Do not mess with the
+   last nine entries of the table unless you know what you are doing. *)
+val const_trans_table =
+  Symtab.make [(@{type_name Product_Type.prod}, "prod"),
+               (@{type_name Sum_Type.sum}, "sum"),
+               (@{const_name HOL.eq}, "equal"),
+               (@{const_name HOL.conj}, "and"),
+               (@{const_name HOL.disj}, "or"),
+               (@{const_name HOL.implies}, "implies"),
+               (@{const_name Set.member}, "member"),
+               (@{const_name fequal}, "fequal"),
+               (@{const_name COMBI}, "COMBI"),
+               (@{const_name COMBK}, "COMBK"),
+               (@{const_name COMBB}, "COMBB"),
+               (@{const_name COMBC}, "COMBC"),
+               (@{const_name COMBS}, "COMBS"),
+               (@{const_name True}, "True"),
+               (@{const_name False}, "False"),
+               (@{const_name If}, "If")]
+
+(* Invert the table of translations between Isabelle and ATPs. *)
+val const_trans_table_inv =
+  Symtab.update ("fequal", @{const_name HOL.eq})
+                (Symtab.make (map swap (Symtab.dest const_trans_table)))
+
+val invert_const = perhaps (Symtab.lookup const_trans_table_inv)
+
+(*Escaping of special characters.
+  Alphanumeric characters are left unchanged.
+  The character _ goes to __
+  Characters in the range ASCII space to / go to _A to _P, respectively.
+  Other characters go to _nnn where nnn is the decimal ASCII code.*)
+val A_minus_space = Char.ord #"A" - Char.ord #" ";
+
+fun stringN_of_int 0 _ = ""
+  | stringN_of_int k n = stringN_of_int (k-1) (n div 10) ^ Int.toString (n mod 10);
+
+fun ascii_of_c c =
+  if Char.isAlphaNum c then String.str c
+  else if c = #"_" then "__"
+  else if #" " <= c andalso c <= #"/"
+       then "_" ^ String.str (Char.chr (Char.ord c + A_minus_space))
+  else ("_" ^ stringN_of_int 3 (Char.ord c))  (*fixed width, in case more digits follow*)
+
+val ascii_of = String.translate ascii_of_c;
+
+(** Remove ASCII armouring from names in proof files **)
+
+(*We don't raise error exceptions because this code can run inside the watcher.
+  Also, the errors are "impossible" (hah!)*)
+fun unascii_aux rcs [] = String.implode(rev rcs)
+  | unascii_aux rcs [#"_"] = unascii_aux (#"_"::rcs) []  (*ERROR*)
+      (*Three types of _ escapes: __, _A to _P, _nnn*)
+  | unascii_aux rcs (#"_" :: #"_" :: cs) = unascii_aux (#"_"::rcs) cs
+  | unascii_aux rcs (#"_" :: c :: cs) =
+      if #"A" <= c andalso c<= #"P"  (*translation of #" " to #"/"*)
+      then unascii_aux (Char.chr(Char.ord c - A_minus_space) :: rcs) cs
+      else
+        let val digits = List.take (c::cs, 3) handle Subscript => []
+        in
+            case Int.fromString (String.implode digits) of
+                NONE => unascii_aux (c:: #"_"::rcs) cs  (*ERROR*)
+              | SOME n => unascii_aux (Char.chr n :: rcs) (List.drop (cs, 2))
+        end
+  | unascii_aux rcs (c::cs) = unascii_aux (c::rcs) cs
+val unascii_of = unascii_aux [] o String.explode
+
+(* If string s has the prefix s1, return the result of deleting it,
+   un-ASCII'd. *)
+fun strip_prefix_and_unascii s1 s =
+  if String.isPrefix s1 s then
+    SOME (unascii_of (String.extract (s, size s1, NONE)))
+  else
+    NONE
+
+(*Remove the initial ' character from a type variable, if it is present*)
+fun trim_type_var s =
+  if s <> "" andalso String.sub(s,0) = #"'" then String.extract(s,1,NONE)
+  else error ("trim_type: Malformed type variable encountered: " ^ s);
+
+fun ascii_of_indexname (v,0) = ascii_of v
+  | ascii_of_indexname (v,i) = ascii_of v ^ "_" ^ Int.toString i;
+
+fun make_bound_var x = bound_var_prefix ^ ascii_of x
+fun make_schematic_var v = schematic_var_prefix ^ ascii_of_indexname v
+fun make_fixed_var x = fixed_var_prefix ^ ascii_of x
+
+fun make_schematic_type_var (x,i) =
+      tvar_prefix ^ (ascii_of_indexname (trim_type_var x,i));
+fun make_fixed_type_var x = tfree_prefix ^ (ascii_of (trim_type_var x));
+
+fun lookup_const c =
+  case Symtab.lookup const_trans_table c of
+    SOME c' => c'
+  | NONE => ascii_of c
+
+(* HOL.eq MUST BE "equal" because it's built into ATPs. *)
+fun make_fixed_const @{const_name HOL.eq} = "equal"
+  | make_fixed_const c = const_prefix ^ lookup_const c
+
+fun make_fixed_type_const c = type_const_prefix ^ lookup_const c
+
+fun make_type_class clas = class_prefix ^ ascii_of clas;
+
+(* The number of type arguments of a constant, zero if it's monomorphic. For
+   (instances of) Skolem pseudoconstants, this information is encoded in the
+   constant name. *)
+fun num_type_args thy s =
+  if String.isPrefix skolem_const_prefix s then
+    s |> space_explode Long_Name.separator |> List.last |> Int.fromString |> the
+  else
+    (s, Sign.the_const_type thy s) |> Sign.const_typargs thy |> length
+
+fun new_skolem_var_from_const s =
+  let
+    val ss = s |> space_explode Long_Name.separator
+    val n = length ss
+  in (nth ss (n - 2), nth ss (n - 3) |> Int.fromString |> the) end
+
+
+(**** Definitions and functions for FOL clauses for TPTP format output ****)
+
+type name = string * string
+
+(**** Isabelle FOL clauses ****)
+
+(* The first component is the type class; the second is a TVar or TFree. *)
+datatype type_literal =
+  TyLitVar of name * name |
+  TyLitFree of name * name
+
+(*Make literals for sorted type variables*)
+fun sorts_on_typs_aux (_, [])   = []
+  | sorts_on_typs_aux ((x,i),  s::ss) =
+      let val sorts = sorts_on_typs_aux ((x,i), ss)
+      in
+          if s = "HOL.type" then sorts
+          else if i = ~1 then TyLitFree (`make_type_class s, `make_fixed_type_var x) :: sorts
+          else TyLitVar (`make_type_class s, (make_schematic_type_var (x,i), x)) :: sorts
+      end;
+
+fun sorts_on_typs (TFree (a,s)) = sorts_on_typs_aux ((a,~1),s)
+  | sorts_on_typs (TVar (v,s))  = sorts_on_typs_aux (v,s);
+
+(*Given a list of sorted type variables, return a list of type literals.*)
+fun type_literals_for_types Ts =
+  fold (union (op =)) (map sorts_on_typs Ts) []
+
+(** make axiom and conjecture clauses. **)
+
+(**** Isabelle arities ****)
+
+datatype arLit =
+  TConsLit of name * name * name list |
+  TVarLit of name * name
+
+datatype arity_clause =
+  ArityClause of {name: string, conclLit: arLit, premLits: arLit list}
+
+
+fun gen_TVars 0 = []
+  | gen_TVars n = ("T_" ^ Int.toString n) :: gen_TVars (n-1);
+
+fun pack_sort(_,[])  = []
+  | pack_sort(tvar, "HOL.type"::srt) = pack_sort (tvar, srt)   (*IGNORE sort "type"*)
+  | pack_sort(tvar, cls::srt) =
+    (`make_type_class cls, (tvar, tvar)) :: pack_sort (tvar, srt)
+
+(*Arity of type constructor tcon :: (arg1,...,argN)res*)
+fun make_axiom_arity_clause (tcons, name, (cls,args)) =
+  let
+    val tvars = gen_TVars (length args)
+    val tvars_srts = ListPair.zip (tvars, args)
+  in
+    ArityClause {name = name,
+                 conclLit = TConsLit (`make_type_class cls,
+                                      `make_fixed_type_const tcons,
+                                      tvars ~~ tvars),
+                 premLits = map TVarLit (union_all (map pack_sort tvars_srts))}
+  end
+
+
+(**** Isabelle class relations ****)
+
+datatype class_rel_clause =
+  ClassRelClause of {name: string, subclass: name, superclass: name}
+
+(*Generate all pairs (sub,super) such that sub is a proper subclass of super in theory thy.*)
+fun class_pairs _ [] _ = []
+  | class_pairs thy subs supers =
+      let
+        val class_less = Sorts.class_less (Sign.classes_of thy)
+        fun add_super sub super = class_less (sub, super) ? cons (sub, super)
+        fun add_supers sub = fold (add_super sub) supers
+      in fold add_supers subs [] end
+
+fun make_class_rel_clause (sub,super) =
+  ClassRelClause {name = sub ^ "_" ^ super,
+                  subclass = `make_type_class sub,
+                  superclass = `make_type_class super}
+
+fun make_class_rel_clauses thy subs supers =
+  map make_class_rel_clause (class_pairs thy subs supers);
+
+
+(** Isabelle arities **)
+
+fun arity_clause _ _ (_, []) = []
+  | arity_clause seen n (tcons, ("HOL.type",_)::ars) =  (*ignore*)
+      arity_clause seen n (tcons,ars)
+  | arity_clause seen n (tcons, (ar as (class,_)) :: ars) =
+      if member (op =) seen class then (*multiple arities for the same tycon, class pair*)
+          make_axiom_arity_clause (tcons, lookup_const tcons ^ "_" ^ class ^ "_" ^ Int.toString n, ar) ::
+          arity_clause seen (n+1) (tcons,ars)
+      else
+          make_axiom_arity_clause (tcons, lookup_const tcons ^ "_" ^ class, ar) ::
+          arity_clause (class::seen) n (tcons,ars)
+
+fun multi_arity_clause [] = []
+  | multi_arity_clause ((tcons, ars) :: tc_arlists) =
+      arity_clause [] 1 (tcons, ars) @ multi_arity_clause tc_arlists
+
+(*Generate all pairs (tycon,class,sorts) such that tycon belongs to class in theory thy
+  provided its arguments have the corresponding sorts.*)
+fun type_class_pairs thy tycons classes =
+  let val alg = Sign.classes_of thy
+      fun domain_sorts tycon = Sorts.mg_domain alg tycon o single
+      fun add_class tycon class =
+        cons (class, domain_sorts tycon class)
+        handle Sorts.CLASS_ERROR _ => I
+      fun try_classes tycon = (tycon, fold (add_class tycon) classes [])
+  in  map try_classes tycons  end;
+
+(*Proving one (tycon, class) membership may require proving others, so iterate.*)
+fun iter_type_class_pairs _ _ [] = ([], [])
+  | iter_type_class_pairs thy tycons classes =
+      let val cpairs = type_class_pairs thy tycons classes
+          val newclasses = union_all (union_all (union_all (map (map #2 o #2) cpairs)))
+            |> subtract (op =) classes |> subtract (op =) HOLogic.typeS
+          val (classes', cpairs') = iter_type_class_pairs thy tycons newclasses
+      in (union (op =) classes' classes, union (op =) cpairs' cpairs) end;
+
+fun make_arity_clauses thy tycons classes =
+  let val (classes', cpairs) = iter_type_class_pairs thy tycons classes
+  in  (classes', multi_arity_clause cpairs)  end;
+
+datatype combtyp =
+  CombTVar of name |
+  CombTFree of name |
+  CombType of name * combtyp list
+
+datatype combterm =
+  CombConst of name * combtyp * combtyp list (* Const and Free *) |
+  CombVar of name * combtyp |
+  CombApp of combterm * combterm
+
+datatype fol_literal = FOLLiteral of bool * combterm
+
+(*********************************************************************)
+(* convert a clause with type Term.term to a clause with type clause *)
+(*********************************************************************)
+
+(*Result of a function type; no need to check that the argument type matches.*)
+fun result_type (CombType (_, [_, tp2])) = tp2
+  | result_type _ = raise Fail "non-function type"
+
+fun combtyp_of (CombConst (_, tp, _)) = tp
+  | combtyp_of (CombVar (_, tp)) = tp
+  | combtyp_of (CombApp (t1, _)) = result_type (combtyp_of t1)
+
+(*gets the head of a combinator application, along with the list of arguments*)
+fun strip_combterm_comb u =
+    let fun stripc (CombApp(t,u), ts) = stripc (t, u::ts)
+        |   stripc  x =  x
+    in stripc(u,[]) end
+
+fun combtype_of (Type (a, Ts)) =
+    let val (folTypes, ts) = combtypes_of Ts in
+      (CombType (`make_fixed_type_const a, folTypes), ts)
+    end
+  | combtype_of (tp as TFree (a, _)) = (CombTFree (`make_fixed_type_var a), [tp])
+  | combtype_of (tp as TVar (x, _)) =
+    (CombTVar (make_schematic_type_var x, string_of_indexname x), [tp])
+and combtypes_of Ts =
+  let val (folTyps, ts) = ListPair.unzip (map combtype_of Ts) in
+    (folTyps, union_all ts)
+  end
+
+(* same as above, but no gathering of sort information *)
+fun simple_combtype_of (Type (a, Ts)) =
+    CombType (`make_fixed_type_const a, map simple_combtype_of Ts)
+  | simple_combtype_of (TFree (a, _)) = CombTFree (`make_fixed_type_var a)
+  | simple_combtype_of (TVar (x, _)) =
+    CombTVar (make_schematic_type_var x, string_of_indexname x)
+
+fun new_skolem_const_name th_no s num_T_args =
+  [new_skolem_const_prefix, string_of_int th_no, s, string_of_int num_T_args]
+  |> space_implode Long_Name.separator
+
+(* Converts a term (with combinators) into a combterm. Also accummulates sort
+   infomation. *)
+fun combterm_from_term thy th_no bs (P $ Q) =
+      let val (P', tsP) = combterm_from_term thy th_no bs P
+          val (Q', tsQ) = combterm_from_term thy th_no bs Q
+      in  (CombApp (P', Q'), union (op =) tsP tsQ)  end
+  | combterm_from_term thy _ _ (Const (c, T)) =
+      let
+        val (tp, ts) = combtype_of T
+        val tvar_list =
+          (if String.isPrefix old_skolem_const_prefix c then
+             [] |> Term.add_tvarsT T |> map TVar
+           else
+             (c, T) |> Sign.const_typargs thy)
+          |> map simple_combtype_of
+        val c' = CombConst (`make_fixed_const c, tp, tvar_list)
+      in  (c',ts)  end
+  | combterm_from_term _ _ _ (Free (v, T)) =
+      let val (tp, ts) = combtype_of T
+          val v' = CombConst (`make_fixed_var v, tp, [])
+      in  (v',ts)  end
+  | combterm_from_term _ th_no _ (Var (v as (s, _), T)) =
+    let
+      val (tp, ts) = combtype_of T
+      val v' =
+        if String.isPrefix Meson_Clausify.new_skolem_var_prefix s then
+          let
+            val tys = T |> strip_type |> swap |> op ::
+            val s' = new_skolem_const_name th_no s (length tys)
+          in
+            CombConst (`make_fixed_const s', tp, map simple_combtype_of tys)
+          end
+        else
+          CombVar ((make_schematic_var v, string_of_indexname v), tp)
+    in (v', ts) end
+  | combterm_from_term _ _ bs (Bound j) =
+      let
+        val (s, T) = nth bs j
+        val (tp, ts) = combtype_of T
+        val v' = CombConst (`make_bound_var s, tp, [])
+      in (v', ts) end
+  | combterm_from_term _ _ _ (Abs _) = raise Fail "HOL clause: Abs"
+
+fun predicate_of thy th_no ((@{const Not} $ P), pos) =
+    predicate_of thy th_no (P, not pos)
+  | predicate_of thy th_no (t, pos) =
+    (combterm_from_term thy th_no [] (Envir.eta_contract t), pos)
+
+fun literals_of_term1 args thy th_no (@{const Trueprop} $ P) =
+    literals_of_term1 args thy th_no P
+  | literals_of_term1 args thy th_no (@{const HOL.disj} $ P $ Q) =
+    literals_of_term1 (literals_of_term1 args thy th_no P) thy th_no Q
+  | literals_of_term1 (lits, ts) thy th_no P =
+    let val ((pred, ts'), pol) = predicate_of thy th_no (P, true) in
+      (FOLLiteral (pol, pred) :: lits, union (op =) ts ts')
+    end
+val literals_of_term = literals_of_term1 ([], [])
+
+fun old_skolem_const_name i j num_T_args =
+  old_skolem_const_prefix ^ Long_Name.separator ^
+  (space_implode Long_Name.separator (map Int.toString [i, j, num_T_args]))
+
+fun conceal_old_skolem_terms i old_skolems t =
+  if exists_Const (curry (op =) @{const_name skolem} o fst) t then
+    let
+      fun aux old_skolems
+              (t as (Const (@{const_name skolem}, Type (_, [_, T])) $ _)) =
+          let
+            val (old_skolems, s) =
+              if i = ~1 then
+                (old_skolems, @{const_name undefined})
+              else case AList.find (op aconv) old_skolems t of
+                s :: _ => (old_skolems, s)
+              | [] =>
+                let
+                  val s = old_skolem_const_name i (length old_skolems)
+                                                (length (Term.add_tvarsT T []))
+                in ((s, t) :: old_skolems, s) end
+          in (old_skolems, Const (s, T)) end
+        | aux old_skolems (t1 $ t2) =
+          let
+            val (old_skolems, t1) = aux old_skolems t1
+            val (old_skolems, t2) = aux old_skolems t2
+          in (old_skolems, t1 $ t2) end
+        | aux old_skolems (Abs (s, T, t')) =
+          let val (old_skolems, t') = aux old_skolems t' in
+            (old_skolems, Abs (s, T, t'))
+          end
+        | aux old_skolems t = (old_skolems, t)
+    in aux old_skolems t end
+  else
+    (old_skolems, t)
+
+fun reveal_old_skolem_terms old_skolems =
+  map_aterms (fn t as Const (s, _) =>
+                 if String.isPrefix old_skolem_const_prefix s then
+                   AList.lookup (op =) old_skolems s |> the
+                   |> map_types Type_Infer.paramify_vars
+                 else
+                   t
+               | t => t)
+
+
+(***************************************************************)
+(* Type Classes Present in the Axiom or Conjecture Clauses     *)
+(***************************************************************)
+
+fun set_insert (x, s) = Symtab.update (x, ()) s
+
+fun add_classes (sorts, cset) = List.foldl set_insert cset (flat sorts)
+
+(*Remove this trivial type class*)
+fun delete_type cset = Symtab.delete_safe (the_single @{sort HOL.type}) cset;
+
+fun tfree_classes_of_terms ts =
+  let val sorts_list = map (map #2 o OldTerm.term_tfrees) ts
+  in  Symtab.keys (delete_type (List.foldl add_classes Symtab.empty sorts_list))  end;
+
+fun tvar_classes_of_terms ts =
+  let val sorts_list = map (map #2 o OldTerm.term_tvars) ts
+  in  Symtab.keys (delete_type (List.foldl add_classes Symtab.empty sorts_list))  end;
+
+(*fold type constructors*)
+fun fold_type_consts f (Type (a, Ts)) x = fold (fold_type_consts f) Ts (f (a,x))
+  | fold_type_consts _ _ x = x;
+
+(*Type constructors used to instantiate overloaded constants are the only ones needed.*)
+fun add_type_consts_in_term thy =
+  let
+    fun aux (Const x) =
+        fold (fold_type_consts set_insert) (Sign.const_typargs thy x)
+      | aux (Abs (_, _, u)) = aux u
+      | aux (Const (@{const_name skolem}, _) $ _) = I
+      | aux (t $ u) = aux t #> aux u
+      | aux _ = I
+  in aux end
+
+fun type_consts_of_terms thy ts =
+  Symtab.keys (fold (add_type_consts_in_term thy) ts Symtab.empty);
+
+(* ------------------------------------------------------------------------- *)
+(* HOL to FOL  (Isabelle to Metis)                                           *)
+(* ------------------------------------------------------------------------- *)
+
+datatype mode = FO | HO | FT  (* first-order, higher-order, fully-typed *)
+
+fun string_of_mode FO = "FO"
+  | string_of_mode HO = "HO"
+  | string_of_mode FT = "FT"
+
+fun fn_isa_to_met_sublevel "equal" = "=" (* FIXME: "c_fequal" *)
+  | fn_isa_to_met_sublevel x = x
+fun fn_isa_to_met_toplevel "equal" = "="
+  | fn_isa_to_met_toplevel x = x
+
+fun metis_lit b c args = (b, (c, args));
+
+fun metis_term_from_combtyp (CombTVar (s, _)) = Metis_Term.Var s
+  | metis_term_from_combtyp (CombTFree (s, _)) = Metis_Term.Fn (s, [])
+  | metis_term_from_combtyp (CombType ((s, _), tps)) =
+    Metis_Term.Fn (s, map metis_term_from_combtyp tps);
+
+(*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 strip_combterm_comb tm of
+      (CombConst ((c, _), _, tys), tms) =>
+        let val tyargs = map metis_term_from_combtyp tys
+            val args   = map hol_term_to_fol_FO tms
+        in Metis_Term.Fn (c, tyargs @ args) end
+    | (CombVar ((v, _), _), []) => Metis_Term.Var v
+    | _ => raise Fail "non-first-order combterm"
+
+fun hol_term_to_fol_HO (CombConst ((a, _), _, tylist)) =
+      Metis_Term.Fn (fn_isa_to_met_sublevel a, map metis_term_from_combtyp tylist)
+  | hol_term_to_fol_HO (CombVar ((s, _), _)) = Metis_Term.Var s
+  | hol_term_to_fol_HO (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 (type_wrapper_name, [tm, metis_term_from_combtyp ty])
+
+fun hol_term_to_fol_FT (CombVar ((s, _), ty)) = wrap_type (Metis_Term.Var s, ty)
+  | hol_term_to_fol_FT (CombConst((a, _), ty, _)) =
+      wrap_type (Metis_Term.Fn(fn_isa_to_met_sublevel a, []), ty)
+  | hol_term_to_fol_FT (tm as CombApp(tm1,tm2)) =
+       wrap_type (Metis_Term.Fn(".", map hol_term_to_fol_FT [tm1,tm2]),
+                  combtyp_of tm)
+
+fun hol_literal_to_fol FO (FOLLiteral (pos, tm)) =
+      let val (CombConst((p, _), _, tys), tms) = strip_combterm_comb tm
+          val tylits = if p = "equal" then [] else map metis_term_from_combtyp tys
+          val lits = map hol_term_to_fol_FO tms
+      in metis_lit pos (fn_isa_to_met_toplevel p) (tylits @ lits) end
+  | hol_literal_to_fol HO (FOLLiteral (pos, tm)) =
+     (case strip_combterm_comb tm of
+          (CombConst(("equal", _), _, _), tms) =>
+            metis_lit pos "=" (map hol_term_to_fol_HO tms)
+        | _ => metis_lit pos "{}" [hol_term_to_fol_HO tm])   (*hBOOL*)
+  | hol_literal_to_fol FT (FOLLiteral (pos, tm)) =
+     (case strip_combterm_comb tm of
+          (CombConst(("equal", _), _, _), tms) =>
+            metis_lit pos "=" (map hol_term_to_fol_FT tms)
+        | _ => metis_lit pos "{}" [hol_term_to_fol_FT tm])   (*hBOOL*);
+
+fun literals_of_hol_term thy th_no mode t =
+      let val (lits, types_sorts) = literals_of_term thy th_no 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_type_literals pos (TyLitVar ((s, _), (s', _))) =
+    metis_lit pos s [Metis_Term.Var s']
+  | metis_of_type_literals pos (TyLitFree ((s, _), (s', _))) =
+    metis_lit pos s [Metis_Term.Fn (s',[])]
+
+fun default_sort _ (TVar _) = false
+  | default_sort ctxt (TFree (x, s)) = (s = the_default [] (Variable.def_sort ctxt (x, ~1)));
+
+fun metis_of_tfree tf =
+  Metis_Thm.axiom (Metis_LiteralSet.singleton (metis_of_type_literals true tf));
+
+fun hol_thm_to_fol is_conjecture th_no ctxt type_lits mode j old_skolems th =
+  let
+    val thy = ProofContext.theory_of ctxt
+    val (old_skolems, (mlits, types_sorts)) =
+     th |> prop_of |> Logic.strip_imp_concl
+        |> conceal_old_skolem_terms j old_skolems
+        ||> (HOLogic.dest_Trueprop #> literals_of_hol_term thy th_no mode)
+  in
+    if is_conjecture then
+      (Metis_Thm.axiom (Metis_LiteralSet.fromList mlits),
+       type_literals_for_types types_sorts, old_skolems)
+    else
+      let
+        val tylits = filter_out (default_sort ctxt) types_sorts
+                     |> type_literals_for_types
+        val mtylits =
+          if type_lits then map (metis_of_type_literals false) tylits else []
+      in
+        (Metis_Thm.axiom (Metis_LiteralSet.fromList(mtylits @ mlits)), [],
+         old_skolems)
+      end
+  end;
+
+val helpers =
+  [("c_COMBI", (false, map (`I) @{thms COMBI_def})),
+   ("c_COMBK", (false, map (`I) @{thms COMBK_def})),
+   ("c_COMBB", (false, map (`I) @{thms COMBB_def})),
+   ("c_COMBC", (false, map (`I) @{thms COMBC_def})),
+   ("c_COMBS", (false, map (`I) @{thms COMBS_def})),
+   ("c_fequal", (false, map (rpair @{thm equal_imp_equal})
+                            @{thms fequal_imp_equal equal_imp_fequal})),
+   ("c_True", (true, map (`I) @{thms True_or_False})),
+   ("c_False", (true, map (`I) @{thms True_or_False})),
+   ("c_If", (true, map (`I) @{thms if_True if_False True_or_False}))]
+
+(* ------------------------------------------------------------------------- *)
+(* Logic maps manage the interface between HOL and first-order logic.        *)
+(* ------------------------------------------------------------------------- *)
+
+type logic_map =
+  {axioms: (Metis_Thm.thm * thm) list,
+   tfrees: type_literal list,
+   old_skolems: (string * term) list}
+
+fun is_quasi_fol_clause thy =
+  Meson.is_fol_term thy o snd o conceal_old_skolem_terms ~1 [] o prop_of
+
+(*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
+    Vartab.fold add (#2 (Variable.constraints_of ctxt)) []
+    |> type_literals_for_types
+  end;
+
+(*Insert non-logical axioms corresponding to all accumulated TFrees*)
+fun add_tfrees {axioms, tfrees, old_skolems} : logic_map =
+     {axioms = map (rpair TrueI o metis_of_tfree) (distinct (op =) tfrees) @
+               axioms,
+      tfrees = tfrees, old_skolems = old_skolems}
+
+(*transform isabelle type / arity clause to metis clause *)
+fun add_type_thm [] lmap = lmap
+  | add_type_thm ((ith, mth) :: cls) {axioms, tfrees, old_skolems} =
+      add_type_thm cls {axioms = (mth, ith) :: axioms, tfrees = tfrees,
+                        old_skolems = old_skolems}
+
+fun const_in_metis c (pred, tm_list) =
+  let
+    fun in_mterm (Metis_Term.Var _) = 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;
+
+(* ARITY CLAUSE *)
+fun m_arity_cls (TConsLit ((c, _), (t, _), args)) =
+    metis_lit true c [Metis_Term.Fn(t, map (Metis_Term.Var o fst) args)]
+  | m_arity_cls (TVarLit ((c, _), (s, _))) =
+    metis_lit false c [Metis_Term.Var s]
+(*TrueI is returned as the Isabelle counterpart because there isn't any.*)
+fun arity_cls (ArityClause {conclLit, premLits, ...}) =
+  (TrueI,
+   Metis_Thm.axiom (Metis_LiteralSet.fromList (map m_arity_cls (conclLit :: premLits))));
+
+(* CLASSREL CLAUSE *)
+fun m_class_rel_cls (subclass, _) (superclass, _) =
+  [metis_lit false subclass [Metis_Term.Var "T"], metis_lit true superclass [Metis_Term.Var "T"]];
+fun class_rel_cls (ClassRelClause {subclass, superclass, ...}) =
+  (TrueI, Metis_Thm.axiom (Metis_LiteralSet.fromList (m_class_rel_cls subclass superclass)));
+
+fun type_ext thy tms =
+  let val subs = tfree_classes_of_terms tms
+      val supers = tvar_classes_of_terms tms
+      and tycons = type_consts_of_terms thy tms
+      val (supers', arity_clauses) = make_arity_clauses thy tycons supers
+      val class_rel_clauses = make_class_rel_clauses thy subs supers'
+  in  map class_rel_cls class_rel_clauses @ map arity_cls arity_clauses
+  end;
+
+(* Function to generate metis clauses, including comb and type clauses *)
+fun build_logic_map mode0 ctxt type_lits cls thss =
+  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 (forall (is_quasi_fol_clause thy)) (cls :: thss) then FO
+          else HO
+        | set_mode FT = FT
+      val mode = set_mode mode0
+      (*transform isabelle clause to metis clause *)
+      fun add_thm th_no is_conjecture (metis_ith, isa_ith)
+                  {axioms, tfrees, old_skolems} : logic_map =
+        let
+          val (mth, tfree_lits, old_skolems) =
+            hol_thm_to_fol is_conjecture th_no ctxt type_lits mode (length axioms)
+                           old_skolems metis_ith
+        in
+           {axioms = (mth, Meson.make_meta_clause isa_ith) :: axioms,
+            tfrees = union (op =) tfree_lits tfrees, old_skolems = old_skolems}
+        end;
+      val lmap = {axioms = [], tfrees = init_tfrees ctxt, old_skolems = []}
+                 |> fold (add_thm 0 true o `I) cls
+                 |> add_tfrees
+                 |> fold (fn (th_no, ths) => fold (add_thm th_no false o `I) ths)
+                         (1 upto length thss ~~ thss)
+      val clause_lists = map (Metis_Thm.clause o #1) (#axioms lmap)
+      fun is_used c =
+        exists (Metis_LiteralSet.exists (const_in_metis c o #2)) clause_lists
+      val lmap =
+        if mode = FO then
+          lmap
+        else
+          let
+            val helper_ths =
+              helpers |> filter (is_used o fst)
+                      |> maps (fn (c, (needs_full_types, thms)) =>
+                                  if not (is_used c) orelse
+                                     needs_full_types andalso mode <> FT then
+                                    []
+                                  else
+                                    thms)
+          in lmap |> fold (add_thm ~1 false) helper_ths end
+  in
+    (mode, add_type_thm (type_ext thy (maps (map prop_of) (cls :: thss))) lmap)
+  end
+
+end;
--- a/src/HOL/Tools/Sledgehammer/metis_reconstruct.ML	Mon Oct 04 22:01:34 2010 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,557 +0,0 @@
-(*  Title:      HOL/Tools/Sledgehammer/metis_reconstruct.ML
-    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
-    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
-    Author:     Jasmin Blanchette, TU Muenchen
-    Copyright   Cambridge University 2007
-
-Proof reconstruction for Metis.
-*)
-
-signature METIS_RECONSTRUCT =
-sig
-  type mode = Metis_Translate.mode
-
-  val trace : bool Unsynchronized.ref
-  val lookth : (Metis_Thm.thm * 'a) list -> Metis_Thm.thm -> 'a
-  val untyped_aconv : term -> term -> bool
-  val replay_one_inference :
-    Proof.context -> mode -> (string * term) list
-    -> Metis_Thm.thm * Metis_Proof.inference -> (Metis_Thm.thm * thm) list
-    -> (Metis_Thm.thm * thm) list
-end;
-
-structure Metis_Reconstruct : METIS_RECONSTRUCT =
-struct
-
-open Metis_Translate
-
-val trace = Unsynchronized.ref false
-fun trace_msg msg = if !trace then tracing (msg ()) else ()
-
-datatype term_or_type = SomeTerm of term | SomeType of typ
-
-fun terms_of [] = []
-  | terms_of (SomeTerm t :: tts) = t :: terms_of tts
-  | terms_of (SomeType _ :: tts) = terms_of tts;
-
-fun types_of [] = []
-  | types_of (SomeTerm (Var ((a,idx), _)) :: 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 (SomeTerm _ :: tts) = types_of tts
-  | types_of (SomeType T :: tts) = T :: types_of tts;
-
-fun apply_list rator nargs rands =
-  let val trands = terms_of rands
-  in  if length trands = nargs then SomeTerm (list_comb(rator, trands))
-      else raise Fail
-        ("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) = Var ((w, 1), T)
-
-(*include the default sort, if available*)
-fun mk_tfree ctxt w =
-  let val ww = "'" ^ w
-  in  TFree(ww, the_default HOLogic.typeS (Variable.def_sort ctxt (ww, ~1)))  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);
-
-fun make_tvar s = TVar (("'" ^ s, 0), HOLogic.typeS)
-
-fun smart_invert_const "fequal" = @{const_name HOL.eq}
-  | smart_invert_const s = invert_const s
-
-fun hol_type_from_metis_term _ (Metis_Term.Var v) =
-     (case strip_prefix_and_unascii tvar_prefix v of
-          SOME w => make_tvar w
-        | NONE   => make_tvar v)
-  | hol_type_from_metis_term ctxt (Metis_Term.Fn(x, tys)) =
-     (case strip_prefix_and_unascii type_const_prefix x of
-          SOME tc => Type (smart_invert_const tc,
-                           map (hol_type_from_metis_term ctxt) tys)
-        | NONE    =>
-      case strip_prefix_and_unascii tfree_prefix x of
-          SOME tf => mk_tfree ctxt tf
-        | NONE    => raise Fail ("hol_type_from_metis_term: " ^ x));
-
-(*Maps metis terms to isabelle terms*)
-fun hol_term_from_metis_PT ctxt fol_tm =
-  let val thy = ProofContext.theory_of ctxt
-      val _ = trace_msg (fn () => "hol_term_from_metis_PT: " ^
-                                  Metis_Term.toString fol_tm)
-      fun tm_to_tt (Metis_Term.Var v) =
-             (case strip_prefix_and_unascii tvar_prefix v of
-                  SOME w => SomeType (make_tvar w)
-                | NONE =>
-              case strip_prefix_and_unascii schematic_var_prefix v of
-                  SOME w => SomeTerm (mk_var (w, HOLogic.typeT))
-                | NONE   => SomeTerm (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
-                             SomeTerm t => SomeTerm (list_comb(t, terms_of (map tm_to_tt rands)))
-                           | _ => raise Fail "tm_to_tt: HO application"
-            end
-        | tm_to_tt (Metis_Term.Fn (fname, args)) = applic_to_tt (fname,args)
-      and applic_to_tt ("=",ts) =
-            SomeTerm (list_comb(Const (@{const_name HOL.eq}, HOLogic.typeT), terms_of (map tm_to_tt ts)))
-        | applic_to_tt (a,ts) =
-            case strip_prefix_and_unascii const_prefix a of
-                SOME b =>
-                  let
-                    val c = smart_invert_const b
-                    val ntypes = num_type_args thy c
-                    val nterms = length ts - ntypes
-                    val tts = map tm_to_tt ts
-                    val tys = types_of (List.take(tts,ntypes))
-                    val t =
-                      if String.isPrefix new_skolem_const_prefix c then
-                        Var (new_skolem_var_from_const c,
-                             Type_Infer.paramify_vars (tl tys ---> hd tys))
-                      else
-                        Const (c, dummyT)
-                  in if length tys = ntypes then
-                         apply_list t nterms (List.drop(tts,ntypes))
-                     else
-                       raise Fail ("Constant " ^ c ^ " expects " ^ Int.toString ntypes ^
-                                   " 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 strip_prefix_and_unascii type_const_prefix a of
-                SOME b =>
-                SomeType (Type (smart_invert_const b, types_of (map tm_to_tt ts)))
-              | NONE => (*Maybe a TFree. Should then check that ts=[].*)
-            case strip_prefix_and_unascii tfree_prefix a of
-                SOME b => SomeType (mk_tfree ctxt b)
-              | NONE => (*a fixed variable? They are Skolem functions.*)
-            case strip_prefix_and_unascii fixed_var_prefix a of
-                SOME b =>
-                  let val opr = Free (b, HOLogic.typeT)
-                  in  apply_list opr (length ts) (map tm_to_tt ts)  end
-              | NONE => raise Fail ("unexpected metis function: " ^ a)
-  in
-    case tm_to_tt fol_tm of
-      SomeTerm t => t
-    | SomeType T => raise TYPE ("fol_tm_to_tt: Term expected", [T], [])
-  end
-
-(*Maps fully-typed metis terms to isabelle terms*)
-fun hol_term_from_metis_FT ctxt fol_tm =
-  let val _ = trace_msg (fn () => "hol_term_from_metis_FT: " ^
-                                  Metis_Term.toString fol_tm)
-      fun cvt (Metis_Term.Fn ("ti", [Metis_Term.Var v, _])) =
-             (case strip_prefix_and_unascii schematic_var_prefix v of
-                  SOME w =>  mk_var(w, dummyT)
-                | NONE   => mk_var(v, dummyT))
-        | cvt (Metis_Term.Fn ("ti", [Metis_Term.Fn ("=",[]), _])) =
-            Const (@{const_name HOL.eq}, HOLogic.typeT)
-        | cvt (Metis_Term.Fn ("ti", [Metis_Term.Fn (x,[]), ty])) =
-           (case strip_prefix_and_unascii const_prefix x of
-                SOME c => Const (smart_invert_const c, dummyT)
-              | NONE => (*Not a constant. Is it a fixed variable??*)
-            case strip_prefix_and_unascii fixed_var_prefix x of
-                SOME v => Free (v, hol_type_from_metis_term ctxt ty)
-              | NONE => raise Fail ("hol_term_from_metis_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 (@{const_name HOL.eq}, HOLogic.typeT), map cvt [tm1,tm2])
-        | cvt (t as Metis_Term.Fn (x, [])) =
-           (case strip_prefix_and_unascii const_prefix x of
-                SOME c => Const (smart_invert_const c, dummyT)
-              | NONE => (*Not a constant. Is it a fixed variable??*)
-            case strip_prefix_and_unascii fixed_var_prefix x of
-                SOME v => Free (v, dummyT)
-              | NONE => (trace_msg (fn () => "hol_term_from_metis_FT bad const: " ^ x);
-                  hol_term_from_metis_PT ctxt t))
-        | cvt t = (trace_msg (fn () => "hol_term_from_metis_FT bad term: " ^ Metis_Term.toString t);
-            hol_term_from_metis_PT ctxt t)
-  in fol_tm |> cvt end
-
-fun hol_term_from_metis FT = hol_term_from_metis_FT
-  | hol_term_from_metis _ = hol_term_from_metis_PT
-
-fun hol_terms_from_fol ctxt mode old_skolems fol_tms =
-  let val ts = map (hol_term_from_metis mode ctxt) 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' = ts |> map (reveal_old_skolem_terms old_skolems)
-                   |> infer_types ctxt
-      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;
-
-(* ------------------------------------------------------------------------- *)
-(* 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));
-*)
-
-fun lookth thpairs (fth : Metis_Thm.thm) =
-  the (AList.lookup (uncurry Metis_Thm.equal) thpairs fth)
-  handle Option.Option =>
-         raise Fail ("Failed to find Metis theorem " ^ Metis_Thm.toString fth)
-
-fun cterm_incr_types thy idx = cterm_of thy o (map_types (Logic.incr_tvar idx));
-
-(* INFERENCE RULE: AXIOM *)
-
-fun axiom_inf thpairs th = Thm.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 *)
-
-val EXCLUDED_MIDDLE = @{lemma "P ==> ~ P ==> False" by (rule notE)}
-
-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 assume_inf ctxt mode old_skolems atm =
-  inst_excluded_middle
-      (ProofContext.theory_of ctxt)
-      (singleton (hol_terms_from_fol ctxt mode old_skolems) (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 old_skolems 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 = the (List.find (fn ((a,_),_) => a=x) i_th_vars)
-      fun subst_translation (x,y) =
-        let val v = find_var x
-            (* We call "reveal_old_skolem_terms" and "infer_types" below. *)
-            val t = hol_term_from_metis mode ctxt y
-        in  SOME (cterm_of thy (Var v), t)  end
-        handle Option.Option =>
-               (trace_msg (fn () => "\"find_var\" failed for " ^ x ^
-                                    " in " ^ Display.string_of_thm ctxt i_th);
-                NONE)
-             | TYPE _ =>
-               (trace_msg (fn () => "\"hol_term_from_metis\" failed for " ^ x ^
-                                    " in " ^ Display.string_of_thm ctxt i_th);
-                NONE)
-      fun remove_typeinst (a, t) =
-            case strip_prefix_and_unascii schematic_var_prefix a of
-                SOME b => SOME (b, t)
-              | NONE => case strip_prefix_and_unascii 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 = rawtms |> map (reveal_old_skolem_terms old_skolems)
-                       |> infer_types ctxt
-      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 end
-  handle THM (msg, _, _) =>
-         error ("Cannot replay Metis proof in Isabelle:\n" ^ msg)
-
-(* 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 thy tha i thb =
-  let
-    val tha = Drule.incr_type_indexes (1 + Thm.maxidx_of thb) tha
-    fun aux tha thb =
-      case Thm.bicompose false (false, tha, nprems_of tha) i thb
-           |> Seq.list_of |> distinct Thm.eq_thm of
-        [th] => th
-      | _ => raise THM ("resolve_inc_tyvars: unique result expected", i,
-                        [tha, thb])
-  in
-    aux tha thb
-    handle TERM z =>
-           (* The unifier, which is invoked from "Thm.bicompose", will sometimes
-              refuse to unify "?a::?'a" with "?a::?'b" or "?a::nat" and throw a
-              "TERM" exception (with "add_ffpair" as first argument). We then
-              perform unification of the types of variables by hand and try
-              again. We could do this the first time around but this error
-              occurs seldom and we don't want to break existing proofs in subtle
-              ways or slow them down needlessly. *)
-           case [] |> fold (Term.add_vars o prop_of) [tha, thb]
-                   |> AList.group (op =)
-                   |> maps (fn ((s, _), T :: Ts) =>
-                               map (fn T' => (Free (s, T), Free (s, T'))) Ts)
-                   |> rpair (Envir.empty ~1)
-                   |-> fold (Pattern.unify thy)
-                   |> Envir.type_env |> Vartab.dest
-                   |> map (fn (x, (S, T)) =>
-                              pairself (ctyp_of thy) (TVar (x, S), T)) of
-             [] => raise TERM z
-           | ps => aux (instantiate (ps, []) tha) (instantiate (ps, []) thb)
-  end
-
-fun mk_not (Const (@{const_name Not}, _) $ b) = b
-  | mk_not b = HOLogic.mk_not b
-
-(* 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, for some reason. *)
-  | untyped_aconv (Bound i) (Bound j) = (i = j)
-  | untyped_aconv (Abs (_, _, t)) (Abs (_, _, u)) = 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 literal_index lit =
-  let
-    val lit = Envir.eta_contract lit
-    fun get _ [] = 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
-
-(* Permute a rule's premises to move the i-th premise to the last position. *)
-fun make_last i th =
-  let val n = nprems_of th
-  in  if 1 <= i andalso i <= n
-      then Thm.permute_prems (i-1) 1 th
-      else raise THM("select_literal", i, [th])
-  end;
-
-(* Maps a rule that ends "... ==> P ==> False" to "... ==> ~P" while suppressing
-   double-negations. *)
-val negate_head = rewrite_rule [@{thm atomize_not}, not_not RS eq_reflection]
-
-(* Maps the clause  [P1,...Pn]==>False to [P1,...,P(i-1),P(i+1),...Pn] ==> ~P *)
-val select_literal = negate_head oo make_last
-
-fun resolve_inf ctxt mode old_skolems 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
-    (* Trivial cases where one operand is type info *)
-    if Thm.eq_thm (TrueI, i_th1) then
-      i_th2
-    else if Thm.eq_thm (TrueI, i_th2) then
-      i_th1
-    else
-      let
-        val i_atm = singleton (hol_terms_from_fol ctxt mode old_skolems)
-                              (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 = literal_index (mk_not i_atm) prems_th1
-              handle Empty => raise Fail "Failed to find literal in th1"
-        val _ = trace_msg (fn () => "  index_th1: " ^ Int.toString index_th1)
-        val index_th2 = literal_index i_atm prems_th2
-              handle Empty => raise Fail "Failed to find literal in th2"
-        val _ = trace_msg (fn () => "  index_th2: " ^ Int.toString index_th2)
-    in
-      resolve_inc_tyvars thy (select_literal index_th1 i_th1) index_th2 i_th2
-    end
-  end;
-
-(* INFERENCE RULE: REFL *)
-
-val REFL_THM = Thm.incr_indexes 2 @{lemma "t ~= t ==> False" by simp}
-
-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 old_skolems t =
-  let val thy = ProofContext.theory_of ctxt
-      val i_t = singleton (hol_terms_from_fol ctxt mode old_skolems) 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;
-
-(* INFERENCE RULE: EQUALITY *)
-
-val subst_em = @{lemma "s = t ==> P s ==> ~ P t ==> False" by simp}
-val ssubst_em = @{lemma "s = t ==> P t ==> ~ P s ==> False" by simp}
-
-val metis_eq = Metis_Term.Fn ("=", []);
-
-fun get_ty_arg_size _ (Const (@{const_name HOL.eq}, _)) = 0  (*equality has no type arguments*)
-  | get_ty_arg_size thy (Const (c, _)) = (num_type_args thy c handle TYPE _ => 0)
-  | get_ty_arg_size _ _ = 0;
-
-fun equality_inf ctxt mode old_skolems (pos, atm) fp fr =
-  let val thy = ProofContext.theory_of ctxt
-      val m_tm = Metis_Term.Fn atm
-      val [i_atm,i_tm] = hol_terms_from_fol ctxt mode old_skolems [m_tm, fr]
-      val _ = trace_msg (fn () => "sign of the literal: " ^ Bool.toString pos)
-      fun replace_item_list lx 0 (_::ls) = lx::ls
-        | replace_item_list lx i (l::ls) = l :: replace_item_list lx (i-1) ls
-      fun path_finder_FO tm [] = (tm, Bound 0)
-        | path_finder_FO tm (p::ps) =
-            let val (tm1,args) = 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 ("Cannot replay Metis proof in Isabelle:\n" ^
-                                "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, Bound 0)
-        | path_finder_HO (t$u) (0::ps) = (fn(x,y) => (x, y$u)) (path_finder_HO t ps)
-        | path_finder_HO (t$u) (_::ps) = (fn(x,y) => (x, t$y)) (path_finder_HO u ps)
-        | path_finder_HO tm ps =
-          raise Fail ("Cannot replay Metis proof in Isabelle:\n" ^
-                      "equality_inf, path_finder_HO: path = " ^
-                      space_implode " " (map Int.toString ps) ^
-                      " isa-term: " ^  Syntax.string_of_term ctxt tm)
-      fun path_finder_FT tm [] _ = (tm, Bound 0)
-        | path_finder_FT tm (0::ps) (Metis_Term.Fn ("ti", [t1, _])) =
-            path_finder_FT tm ps t1
-        | path_finder_FT (t$u) (0::ps) (Metis_Term.Fn (".", [t1, _])) =
-            (fn(x,y) => (x, y$u)) (path_finder_FT t ps t1)
-        | path_finder_FT (t$u) (1::ps) (Metis_Term.Fn (".", [_, t2])) =
-            (fn(x,y) => (x, t$y)) (path_finder_FT u ps t2)
-        | path_finder_FT tm ps t =
-          raise Fail ("Cannot replay Metis proof in Isabelle:\n" ^
-                      "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(@{const_name HOL.eq},_) $ _ $ _) (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 (_ :: ps) (Metis_Term.Fn ("{}", [_])) =
-             path_finder_HO tm ps      (*if not equality, ignore head to skip hBOOL*)
-        | path_finder FT (tm as Const(@{const_name HOL.eq}, _) $ _ $ _) (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 (_ :: 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 Const (@{const_name 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 = Abs ("x", 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' = Thm.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;
-
-fun step ctxt mode old_skolems thpairs p =
-  case p of
-    (fol_th, Metis_Proof.Axiom _) => factor (axiom_inf thpairs fol_th)
-  | (_, Metis_Proof.Assume f_atm) => assume_inf ctxt mode old_skolems f_atm
-  | (_, Metis_Proof.Metis_Subst (f_subst, f_th1)) =>
-    factor (inst_inf ctxt mode old_skolems thpairs f_subst f_th1)
-  | (_, Metis_Proof.Resolve(f_atm, f_th1, f_th2)) =>
-    factor (resolve_inf ctxt mode old_skolems thpairs f_atm f_th1 f_th2)
-  | (_, Metis_Proof.Refl f_tm) => refl_inf ctxt mode old_skolems f_tm
-  | (_, Metis_Proof.Equality (f_lit, f_p, f_r)) =>
-    equality_inf ctxt mode old_skolems f_lit f_p f_r
-
-fun flexflex_first_order th =
-  case Thm.tpairs_of th of
-      [] => th
-    | pairs =>
-        let val thy = theory_of_thm th
-            val (_, tenv) =
-              fold (Pattern.first_order_match thy) pairs (Vartab.empty, Vartab.empty)
-            val t_pairs = map Meson.term_pair_of (Vartab.dest tenv)
-            val th' = Thm.instantiate ([], map (pairself (cterm_of thy)) t_pairs) th
-        in  th'  end
-        handle THM _ => th;
-
-fun is_metis_literal_genuine (_, (s, _)) = not (String.isPrefix class_prefix s)
-fun is_isabelle_literal_genuine t =
-  case t of _ $ (Const (@{const_name skolem}, _) $ _) => false | _ => true
-
-fun count p xs = fold (fn x => if p x then Integer.add 1 else I) xs 0
-
-fun replay_one_inference ctxt mode old_skolems (fol_th, inf) thpairs =
-  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 = step ctxt mode old_skolems thpairs (fol_th, inf)
-             |> flexflex_first_order
-    val _ = trace_msg (fn () => "ISABELLE THM: " ^ Display.string_of_thm ctxt th)
-    val _ = trace_msg (fn () => "=============================================")
-    val num_metis_lits =
-      fol_th |> Metis_Thm.clause |> Metis_LiteralSet.toList
-             |> count is_metis_literal_genuine
-    val num_isabelle_lits =
-      th |> prems_of |> count is_isabelle_literal_genuine
-    val _ = if num_metis_lits = num_isabelle_lits then ()
-            else error "Cannot replay Metis proof in Isabelle: Out of sync."
-  in (fol_th, th) :: thpairs end
-
-end;
--- a/src/HOL/Tools/Sledgehammer/metis_tactics.ML	Mon Oct 04 22:01:34 2010 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,449 +0,0 @@
-(*  Title:      HOL/Tools/Sledgehammer/metis_tactics.ML
-    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
-    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
-    Author:     Jasmin Blanchette, TU Muenchen
-    Copyright   Cambridge University 2007
-
-HOL setup for the Metis prover.
-*)
-
-signature METIS_TACTICS =
-sig
-  val trace : bool Unsynchronized.ref
-  val type_lits : bool Config.T
-  val new_skolemizer : bool Config.T
-  val metis_tac : Proof.context -> thm list -> int -> tactic
-  val metisF_tac : Proof.context -> thm list -> int -> tactic
-  val metisFT_tac : Proof.context -> thm list -> int -> tactic
-  val setup : theory -> theory
-end
-
-structure Metis_Tactics : METIS_TACTICS =
-struct
-
-open Metis_Translate
-open Metis_Reconstruct
-
-structure Int_Pair_Graph =
-  Graph(type key = int * int val ord = prod_ord int_ord int_ord)
-
-fun trace_msg msg = if !trace then tracing (msg ()) else ()
-
-val (type_lits, type_lits_setup) = Attrib.config_bool "metis_type_lits" (K true)
-val (new_skolemizer, new_skolemizer_setup) =
-  Attrib.config_bool "metis_new_skolemizer" (K false)
-
-fun is_false t = t aconv (HOLogic.mk_Trueprop HOLogic.false_const);
-
-fun have_common_thm ths1 ths2 =
-  exists (member Thm.eq_thm ths1) (map Meson.make_meta_clause ths2)
-
-(*Determining which axiom clauses are actually used*)
-fun used_axioms axioms (th, Metis_Proof.Axiom _) = SOME (lookth axioms th)
-  | used_axioms _ _ = NONE;
-
-val clause_params =
-  {ordering = Metis_KnuthBendixOrder.default,
-   orderLiterals = Metis_Clause.UnsignedLiteralOrder,
-   orderTerms = true}
-val active_params =
-  {clause = clause_params,
-   prefactor = #prefactor Metis_Active.default,
-   postfactor = #postfactor Metis_Active.default}
-val waiting_params =
-  {symbolsWeight = 1.0,
-   variablesWeight = 0.0,
-   literalsWeight = 0.0,
-   models = []}
-val resolution_params = {active = active_params, waiting = waiting_params}
-
-fun instantiate_theorem thy inst th =
-  let
-    val tyenv = Vartab.empty |> fold (Type.raw_unify o pairself fastype_of) inst
-    val instT =
-      [] |> Vartab.fold (fn (z, (S, T)) =>
-                            cons (TVar (z, S), Type.devar tyenv T)) tyenv
-    val inst = inst |> map (pairself (subst_atomic_types instT))
-    val _ = tracing (cat_lines (map (fn (T, U) =>
-        Syntax.string_of_typ @{context} T ^ " |-> " ^
-        Syntax.string_of_typ @{context} U) instT))
-    val _ = tracing (cat_lines (map (fn (t, u) =>
-        Syntax.string_of_term @{context} t ^ " |-> " ^
-        Syntax.string_of_term @{context} u) inst))
-    val cinstT = instT |> map (pairself (ctyp_of thy))
-    val cinst = inst |> map (pairself (cterm_of thy))
-  in th |> Thm.instantiate (cinstT, cinst) end
-
-(* In principle, it should be sufficient to apply "assume_tac" to unify the
-   conclusion with one of the premises. However, in practice, this is unreliable
-   because of the mildly higher-order nature of the unification problems.
-   Typical constraints are of the form
-   "?SK_a_b_c_x SK_d_e_f_y ... SK_a_b_c_x ... SK_g_h_i_z =?= SK_a_b_c_x",
-   where the nonvariables are goal parameters. *)
-fun unify_first_prem_with_concl thy i th =
-  let
-    val goal = Logic.get_goal (prop_of th) i |> Envir.beta_eta_contract
-    val prem = goal |> Logic.strip_assums_hyp |> hd
-    val concl = goal |> Logic.strip_assums_concl
-    fun pair_untyped_aconv (t1, t2) (u1, u2) =
-      untyped_aconv t1 u1 andalso untyped_aconv t2 u2
-    fun add_terms tp inst =
-      if exists (pair_untyped_aconv tp) inst then inst
-      else tp :: map (apsnd (subst_atomic [tp])) inst
-    fun is_flex t =
-      case strip_comb t of
-        (Var _, args) => forall is_Bound args
-      | _ => false
-    fun unify_flex flex rigid =
-      case strip_comb flex of
-        (Var (z as (_, T)), args) =>
-        add_terms (Var z,
-          fold_rev (curry absdummy) (take (length args) (binder_types T)) rigid)
-      | _ => raise TERM ("unify_flex: expected flex", [flex])
-    fun unify_potential_flex comb atom =
-      if is_flex comb then unify_flex comb atom
-      else if is_Var atom then add_terms (atom, comb)
-      else raise TERM ("unify_terms", [comb, atom])
-    fun unify_terms (t, u) =
-      case (t, u) of
-        (t1 $ t2, u1 $ u2) =>
-        if is_flex t then unify_flex t u
-        else if is_flex u then unify_flex u t
-        else fold unify_terms [(t1, u1), (t2, u2)]
-      | (_ $ _, _) => unify_potential_flex t u
-      | (_, _ $ _) => unify_potential_flex u t
-      | (Var _, _) => add_terms (t, u)
-      | (_, Var _) => add_terms (u, t)
-      | _ => if untyped_aconv t u then I else raise TERM ("unify_terms", [t, u])
-  in th |> instantiate_theorem thy (unify_terms (prem, concl) []) end
-
-fun shuffle_key (((axiom_no, (_, index_no)), _), _) = (index_no, axiom_no)
-fun shuffle_ord p =
-  rev_order (prod_ord int_ord int_ord (pairself shuffle_key p))
-
-val copy_prem = @{lemma "P ==> (P ==> P ==> Q) ==> Q" by fast}
-
-fun copy_prems_tac [] ns i =
-    if forall (curry (op =) 1) ns then all_tac else copy_prems_tac (rev ns) [] i
-  | copy_prems_tac (1 :: ms) ns i =
-    rotate_tac 1 i THEN copy_prems_tac ms (1 :: ns) i
-  | copy_prems_tac (m :: ms) ns i =
-    etac copy_prem i THEN copy_prems_tac ms (m div 2 :: (m + 1) div 2 :: ns) i
-
-fun instantiate_forall_tac thy params t i =
-  let
-    fun repair (t as (Var ((s, _), _))) =
-        (case find_index (fn ((s', _), _) => s' = s) params of
-           ~1 => t
-         | j => Bound j)
-      | repair (t $ u) = repair t $ repair u
-      | repair t = t
-    val t' = t |> repair |> fold (curry absdummy) (map snd params)
-    fun do_instantiate th =
-      let val var = Term.add_vars (prop_of th) [] |> the_single in
-        th |> instantiate_theorem thy [(Var var, t')]
-      end
-  in
-    etac @{thm allE} i
-    THEN rotate_tac ~1 i
-    THEN PRIMITIVE do_instantiate
-  end
-
-fun release_clusters_tac _ _ _ _ [] = K all_tac
-  | release_clusters_tac thy ax_counts substs params
-                         ((ax_no, cluster_no) :: clusters) =
-    let
-      fun in_right_cluster s =
-        (s |> Meson_Clausify.cluster_of_zapped_var_name |> fst |> snd |> fst)
-        = cluster_no
-      val cluster_substs =
-        substs
-        |> map_filter (fn (ax_no', (_, (_, tsubst))) =>
-                          if ax_no' = ax_no then
-                            tsubst |> filter (in_right_cluster
-                                               o fst o fst o dest_Var o fst)
-                                    |> map snd |> SOME
-                           else
-                             NONE)
-      val n = length cluster_substs
-      fun do_cluster_subst cluster_subst =
-        map (instantiate_forall_tac thy params) cluster_subst @ [rotate_tac 1]
-      val params' = params (* FIXME ### existentials! *)
-      val first_prem = find_index (fn (ax_no', _) => ax_no' = ax_no) substs
-    in
-      rotate_tac first_prem
-      THEN' (EVERY' (maps do_cluster_subst cluster_substs))
-      THEN' rotate_tac (~ first_prem - length cluster_substs)
-      THEN' release_clusters_tac thy ax_counts substs params' clusters
-    end
-
-val cluster_ord =
-  prod_ord (prod_ord int_ord (prod_ord int_ord int_ord)) bool_ord
-
-val tysubst_ord =
-  list_ord (prod_ord Term_Ord.fast_indexname_ord
-                     (prod_ord Term_Ord.sort_ord Term_Ord.typ_ord))
-
-structure Int_Tysubst_Table =
-  Table(type key = int * (indexname * (sort * typ)) list
-        val ord = prod_ord int_ord tysubst_ord)
-
-(* Attempts to derive the theorem "False" from a theorem of the form
-   "P1 ==> ... ==> Pn ==> False", where the "Pi"s are to be discharged using the
-   specified axioms. The axioms have leading "All" and "Ex" quantifiers, which
-   must be eliminated first. *)
-fun discharge_skolem_premises ctxt axioms prems_imp_false =
-  if prop_of prems_imp_false aconv @{prop False} then
-    prems_imp_false
-  else
-    let
-      val thy = ProofContext.theory_of ctxt
-      (* distinguish variables with same name but different types *)
-      val prems_imp_false' =
-        prems_imp_false |> try (forall_intr_vars #> gen_all)
-                        |> the_default prems_imp_false
-      val prems_imp_false =
-        if prop_of prems_imp_false aconv prop_of prems_imp_false' then
-          prems_imp_false
-        else
-          prems_imp_false'
-      fun match_term p =
-        let
-          val (tyenv, tenv) =
-            Pattern.first_order_match thy p (Vartab.empty, Vartab.empty)
-          val tsubst =
-            tenv |> Vartab.dest
-                 |> sort (cluster_ord
-                          o pairself (Meson_Clausify.cluster_of_zapped_var_name
-                                      o fst o fst))
-                 |> map (Meson.term_pair_of
-                         #> pairself (Envir.subst_term_types tyenv))
-          val tysubst = tyenv |> Vartab.dest
-        in (tysubst, tsubst) end
-      fun subst_info_for_prem subgoal_no prem =
-        case prem of
-          _ $ (Const (@{const_name skolem}, _) $ (_ $ t $ num)) =>
-          let val ax_no = HOLogic.dest_nat num in
-            (ax_no, (subgoal_no,
-                     match_term (nth axioms ax_no |> the |> snd, t)))
-          end
-        | _ => raise TERM ("discharge_skolem_premises: Malformed premise",
-                           [prem])
-      fun cluster_of_var_name skolem s =
-        let
-          val ((ax_no, (cluster_no, _)), skolem') =
-            Meson_Clausify.cluster_of_zapped_var_name s
-        in
-          if skolem' = skolem andalso cluster_no > 0 then
-            SOME (ax_no, cluster_no)
-          else
-            NONE
-        end
-      fun clusters_in_term skolem t =
-        Term.add_var_names t [] |> map_filter (cluster_of_var_name skolem o fst)
-      fun deps_for_term_subst (var, t) =
-        case clusters_in_term false var of
-          [] => NONE
-        | [(ax_no, cluster_no)] =>
-          SOME ((ax_no, cluster_no),
-                clusters_in_term true t
-                |> cluster_no > 1 ? cons (ax_no, cluster_no - 1))
-        | _ => raise TERM ("discharge_skolem_premises: Expected Var", [var])
-      val prems = Logic.strip_imp_prems (prop_of prems_imp_false)
-      val substs = prems |> map2 subst_info_for_prem (1 upto length prems)
-                         |> sort (int_ord o pairself fst)
-      val depss = maps (map_filter deps_for_term_subst o snd o snd o snd) substs
-      val clusters = maps (op ::) depss
-      val ordered_clusters =
-        Int_Pair_Graph.empty
-        |> fold Int_Pair_Graph.default_node (map (rpair ()) clusters)
-        |> fold Int_Pair_Graph.add_deps_acyclic depss
-        |> Int_Pair_Graph.topological_order
-        handle Int_Pair_Graph.CYCLES _ =>
-               error "Cannot replay Metis proof in Isabelle without axiom of \
-                     \choice."
-      val params0 =
-        [] |> fold (Term.add_vars o snd) (map_filter I axioms)
-           |> map (`(Meson_Clausify.cluster_of_zapped_var_name o fst o fst))
-           |> filter (fn (((_, (cluster_no, _)), skolem), _) =>
-                         cluster_no = 0 andalso skolem)
-           |> sort shuffle_ord |> map snd
-      val ax_counts =
-        Int_Tysubst_Table.empty
-        |> fold (fn (ax_no, (_, (tysubst, _))) =>
-                    Int_Tysubst_Table.map_default ((ax_no, tysubst), 0)
-                                                  (Integer.add 1)) substs
-        |> Int_Tysubst_Table.dest
-(* for debugging:
-      fun string_for_subst_info (ax_no, (subgoal_no, (tysubst, tsubst))) =
-        "ax: " ^ string_of_int ax_no ^ "; asm: " ^ string_of_int subgoal_no ^
-        "; tysubst: " ^ PolyML.makestring tysubst ^ "; tsubst: {" ^
-        commas (map ((fn (s, t) => s ^ " |-> " ^ t)
-                     o pairself (Syntax.string_of_term ctxt)) tsubst) ^ "}"
-      val _ = tracing ("SUBSTS (" ^ string_of_int (length substs) ^ "):\n" ^
-                       cat_lines (map string_for_subst_info substs))
-      val _ = tracing ("OUTERMOST SKOLEMS: " ^ PolyML.makestring params0)
-      val _ = tracing ("ORDERED CLUSTERS: " ^ PolyML.makestring ordered_clusters)
-      val _ = tracing ("AXIOM COUNTS: " ^ PolyML.makestring ax_counts)
-*)
-      fun rotation_for_subgoal i =
-        find_index (fn (_, (subgoal_no, _)) => subgoal_no = i) substs
-    in
-      Goal.prove ctxt [] [] @{prop False}
-          (K (cut_rules_tac
-                  (map (fst o the o nth axioms o fst o fst) ax_counts) 1
-              THEN print_tac "cut:"
-              THEN TRY (REPEAT_ALL_NEW (etac @{thm exE}) 1)
-              THEN copy_prems_tac (map snd ax_counts) [] 1
-              THEN print_tac "eliminated exist and copied prems:"
-              THEN release_clusters_tac thy ax_counts substs params0
-                                        ordered_clusters 1
-              THEN print_tac "released clusters:"
-              THEN match_tac [prems_imp_false] 1
-              THEN print_tac "applied rule:"
-              THEN ALLGOALS (fn i =>
-                       rtac @{thm skolem_COMBK_I} i
-                       THEN rotate_tac (rotation_for_subgoal i) i
-                       THEN PRIMITIVE (unify_first_prem_with_concl thy i)
-                       THEN assume_tac i)))
-    end
-
-(* Main function to start Metis proof and reconstruction *)
-fun FOL_SOLVE mode ctxt cls ths0 =
-  let val thy = ProofContext.theory_of ctxt
-      val type_lits = Config.get ctxt type_lits
-      val new_skolemizer =
-        Config.get ctxt new_skolemizer orelse null (Meson_Choices.get ctxt)
-      val th_cls_pairs =
-        map2 (fn j => fn th =>
-                (Thm.get_name_hint th,
-                 Meson_Clausify.cnf_axiom ctxt new_skolemizer j th))
-             (0 upto length ths0 - 1) ths0
-      val thss = map (snd o snd) th_cls_pairs
-      val dischargers = map (fst o snd) 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 (app (fn th => trace_msg (fn () => Display.string_of_thm ctxt th))) thss
-      val (mode, {axioms, tfrees, old_skolems}) =
-        build_logic_map mode ctxt type_lits cls thss
-      val _ = if null tfrees then ()
-              else (trace_msg (fn () => "TFREE CLAUSES");
-                    app (fn TyLitFree ((s, _), (s', _)) =>
-                            trace_msg (fn () => s ^ "(" ^ s' ^ ")")) 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 filter (is_false o prop_of) cls of
-          false_th::_ => [false_th RS @{thm FalseE}]
-        | [] =>
-      case Metis_Resolution.new resolution_params {axioms = thms, conjecture = []}
-           |> Metis_Resolution.loop 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 =
-                  fold (replay_one_inference ctxt' mode old_skolems) proof axioms
-                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 = th_cls_pairs |> map_filter (fn (name, (_, cls)) =>
-                  if have_common_thm used cls then NONE else SOME name)
-            in
-                if not (null cls) andalso not (have_common_thm used cls) then
-                  warning "Metis: The assumptions are inconsistent."
-                else
-                  ();
-                if not (null unused) then
-                  warning ("Metis: Unused theorems: " ^ commas_quote unused
-                           ^ ".")
-                else
-                  ();
-                case result of
-                    (_,ith)::_ =>
-                        (trace_msg (fn () => "Success: " ^ Display.string_of_thm ctxt ith);
-                         [discharge_skolem_premises ctxt dischargers ith])
-                  | _ => (trace_msg (fn () => "Metis: No result"); [])
-            end
-        | Metis_Resolution.Satisfiable _ =>
-            (trace_msg (fn () => "Metis: No first-order proof with the lemmas supplied");
-             [])
-  end;
-
-(* Extensionalize "th", because that makes sense and that's what Sledgehammer
-   does, but also keep an unextensionalized version of "th" for backward
-   compatibility. *)
-fun also_extensionalize_theorem th =
-  let val th' = Meson_Clausify.extensionalize_theorem th in
-    if Thm.eq_thm (th, th') then [th]
-    else th :: Meson.make_clauses_unsorted [th']
-  end
-
-val neg_clausify =
-  single
-  #> Meson.make_clauses_unsorted
-  #> maps also_extensionalize_theorem
-  #> map Meson_Clausify.introduce_combinators_in_theorem
-  #> Meson.finish_cnf
-
-fun preskolem_tac ctxt st0 =
-  (if exists (Meson.has_too_many_clauses ctxt)
-             (Logic.prems_of_goal (prop_of st0) 1) then
-     cnf.cnfx_rewrite_tac ctxt 1
-   else
-     all_tac) st0
-
-val type_has_top_sort =
-  exists_subtype (fn TFree (_, []) => true | TVar (_, []) => true | _ => false)
-
-fun generic_metis_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 type_has_top_sort (prop_of st0) then
-      (warning ("Metis: Proof state contains the universal sort {}"); Seq.empty)
-    else
-      Meson.MESON (preskolem_tac ctxt) (maps neg_clausify)
-                  (fn cls => resolve_tac (FOL_SOLVE mode ctxt cls ths) 1)
-                  ctxt i st0
-  end
-
-val metis_tac = generic_metis_tac HO
-val metisF_tac = generic_metis_tac FO
-val metisFT_tac = generic_metis_tac FT
-
-(* Whenever "X" has schematic type variables, we treat "using X by metis" as
-   "by (metis X)", to prevent "Subgoal.FOCUS" from freezing the type variables.
-   We don't do it for nonschematic facts "X" because this breaks a few proofs
-   (in the rare and subtle case where a proof relied on extensionality not being
-   applied) and brings few benefits. *)
-val has_tvar =
-  exists_type (exists_subtype (fn TVar _ => true | _ => false)) o prop_of
-fun method name mode =
-  Method.setup name (Attrib.thms >> (fn ths => fn ctxt =>
-    METHOD (fn facts =>
-               let
-                 val (schem_facts, nonschem_facts) =
-                   List.partition has_tvar facts
-               in
-                 HEADGOAL (Method.insert_tac nonschem_facts THEN'
-                           CHANGED_PROP
-                           o generic_metis_tac mode ctxt (schem_facts @ ths))
-               end)))
-
-val setup =
-  type_lits_setup
-  #> new_skolemizer_setup
-  #> method @{binding metis} HO "Metis for FOL/HOL problems"
-  #> method @{binding metisF} FO "Metis for FOL problems"
-  #> method @{binding metisFT} FT
-            "Metis for FOL/HOL problems with fully-typed translation"
-
-end;
--- a/src/HOL/Tools/Sledgehammer/metis_translate.ML	Mon Oct 04 22:01:34 2010 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,771 +0,0 @@
-(*  Title:      HOL/Tools/Sledgehammer/metis_translate.ML
-    Author:     Jia Meng, Cambridge University Computer Laboratory and NICTA
-    Author:     Kong W. Susanto, Cambridge University Computer Laboratory
-    Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
-    Author:     Jasmin Blanchette, TU Muenchen
-
-Translation of HOL to FOL for Metis.
-*)
-
-signature METIS_TRANSLATE =
-sig
-  type name = string * string
-  datatype type_literal =
-    TyLitVar of name * name |
-    TyLitFree of name * name
-  datatype arLit =
-    TConsLit of name * name * name list |
-    TVarLit of name * name
-  datatype arity_clause =
-    ArityClause of {name: string, conclLit: arLit, premLits: arLit list}
-  datatype class_rel_clause =
-    ClassRelClause of {name: string, subclass: name, superclass: name}
-  datatype combtyp =
-    CombTVar of name |
-    CombTFree of name |
-    CombType of name * combtyp list
-  datatype combterm =
-    CombConst of name * combtyp * combtyp list (* Const and Free *) |
-    CombVar of name * combtyp |
-    CombApp of combterm * combterm
-  datatype fol_literal = FOLLiteral of bool * combterm
-
-  datatype mode = FO | HO | FT
-  type logic_map =
-    {axioms: (Metis_Thm.thm * thm) list,
-     tfrees: type_literal list,
-     old_skolems: (string * term) list}
-
-  val type_wrapper_name : string
-  val bound_var_prefix : string
-  val schematic_var_prefix: string
-  val fixed_var_prefix: string
-  val tvar_prefix: string
-  val tfree_prefix: string
-  val const_prefix: string
-  val type_const_prefix: string
-  val class_prefix: string
-  val new_skolem_const_prefix : string
-  val invert_const: string -> string
-  val ascii_of: string -> string
-  val unascii_of: string -> string
-  val strip_prefix_and_unascii: string -> string -> string option
-  val make_bound_var : string -> string
-  val make_schematic_var : string * int -> string
-  val make_fixed_var : string -> string
-  val make_schematic_type_var : string * int -> string
-  val make_fixed_type_var : string -> string
-  val make_fixed_const : string -> string
-  val make_fixed_type_const : string -> string
-  val make_type_class : string -> string
-  val num_type_args: theory -> string -> int
-  val new_skolem_var_from_const: string -> indexname
-  val type_literals_for_types : typ list -> type_literal list
-  val make_class_rel_clauses :
-    theory -> class list -> class list -> class_rel_clause list
-  val make_arity_clauses :
-    theory -> string list -> class list -> class list * arity_clause list
-  val combtyp_of : combterm -> combtyp
-  val strip_combterm_comb : combterm -> combterm * combterm list
-  val combterm_from_term :
-    theory -> int -> (string * typ) list -> term -> combterm * typ list
-  val reveal_old_skolem_terms : (string * term) list -> term -> term
-  val tfree_classes_of_terms : term list -> string list
-  val tvar_classes_of_terms : term list -> string list
-  val type_consts_of_terms : theory -> term list -> string list
-  val string_of_mode : mode -> string
-  val build_logic_map :
-    mode -> Proof.context -> bool -> thm list -> thm list list
-    -> mode * logic_map
-end
-
-structure Metis_Translate : METIS_TRANSLATE =
-struct
-
-val type_wrapper_name = "ti"
-
-val bound_var_prefix = "B_"
-val schematic_var_prefix = "V_"
-val fixed_var_prefix = "v_"
-
-val tvar_prefix = "T_";
-val tfree_prefix = "t_";
-
-val const_prefix = "c_";
-val type_const_prefix = "tc_";
-val class_prefix = "class_";
-
-val skolem_const_prefix = "Sledgehammer" ^ Long_Name.separator ^ "Sko"
-val old_skolem_const_prefix = skolem_const_prefix ^ "o"
-val new_skolem_const_prefix = skolem_const_prefix ^ "n"
-
-fun union_all xss = fold (union (op =)) xss []
-
-(* Readable names for the more common symbolic functions. Do not mess with the
-   last nine entries of the table unless you know what you are doing. *)
-val const_trans_table =
-  Symtab.make [(@{type_name Product_Type.prod}, "prod"),
-               (@{type_name Sum_Type.sum}, "sum"),
-               (@{const_name HOL.eq}, "equal"),
-               (@{const_name HOL.conj}, "and"),
-               (@{const_name HOL.disj}, "or"),
-               (@{const_name HOL.implies}, "implies"),
-               (@{const_name Set.member}, "member"),
-               (@{const_name fequal}, "fequal"),
-               (@{const_name COMBI}, "COMBI"),
-               (@{const_name COMBK}, "COMBK"),
-               (@{const_name COMBB}, "COMBB"),
-               (@{const_name COMBC}, "COMBC"),
-               (@{const_name COMBS}, "COMBS"),
-               (@{const_name True}, "True"),
-               (@{const_name False}, "False"),
-               (@{const_name If}, "If")]
-
-(* Invert the table of translations between Isabelle and ATPs. *)
-val const_trans_table_inv =
-  Symtab.update ("fequal", @{const_name HOL.eq})
-                (Symtab.make (map swap (Symtab.dest const_trans_table)))
-
-val invert_const = perhaps (Symtab.lookup const_trans_table_inv)
-
-(*Escaping of special characters.
-  Alphanumeric characters are left unchanged.
-  The character _ goes to __
-  Characters in the range ASCII space to / go to _A to _P, respectively.
-  Other characters go to _nnn where nnn is the decimal ASCII code.*)
-val A_minus_space = Char.ord #"A" - Char.ord #" ";
-
-fun stringN_of_int 0 _ = ""
-  | stringN_of_int k n = stringN_of_int (k-1) (n div 10) ^ Int.toString (n mod 10);
-
-fun ascii_of_c c =
-  if Char.isAlphaNum c then String.str c
-  else if c = #"_" then "__"
-  else if #" " <= c andalso c <= #"/"
-       then "_" ^ String.str (Char.chr (Char.ord c + A_minus_space))
-  else ("_" ^ stringN_of_int 3 (Char.ord c))  (*fixed width, in case more digits follow*)
-
-val ascii_of = String.translate ascii_of_c;
-
-(** Remove ASCII armouring from names in proof files **)
-
-(*We don't raise error exceptions because this code can run inside the watcher.
-  Also, the errors are "impossible" (hah!)*)
-fun unascii_aux rcs [] = String.implode(rev rcs)
-  | unascii_aux rcs [#"_"] = unascii_aux (#"_"::rcs) []  (*ERROR*)
-      (*Three types of _ escapes: __, _A to _P, _nnn*)
-  | unascii_aux rcs (#"_" :: #"_" :: cs) = unascii_aux (#"_"::rcs) cs
-  | unascii_aux rcs (#"_" :: c :: cs) =
-      if #"A" <= c andalso c<= #"P"  (*translation of #" " to #"/"*)
-      then unascii_aux (Char.chr(Char.ord c - A_minus_space) :: rcs) cs
-      else
-        let val digits = List.take (c::cs, 3) handle Subscript => []
-        in
-            case Int.fromString (String.implode digits) of
-                NONE => unascii_aux (c:: #"_"::rcs) cs  (*ERROR*)
-              | SOME n => unascii_aux (Char.chr n :: rcs) (List.drop (cs, 2))
-        end
-  | unascii_aux rcs (c::cs) = unascii_aux (c::rcs) cs
-val unascii_of = unascii_aux [] o String.explode
-
-(* If string s has the prefix s1, return the result of deleting it,
-   un-ASCII'd. *)
-fun strip_prefix_and_unascii s1 s =
-  if String.isPrefix s1 s then
-    SOME (unascii_of (String.extract (s, size s1, NONE)))
-  else
-    NONE
-
-(*Remove the initial ' character from a type variable, if it is present*)
-fun trim_type_var s =
-  if s <> "" andalso String.sub(s,0) = #"'" then String.extract(s,1,NONE)
-  else error ("trim_type: Malformed type variable encountered: " ^ s);
-
-fun ascii_of_indexname (v,0) = ascii_of v
-  | ascii_of_indexname (v,i) = ascii_of v ^ "_" ^ Int.toString i;
-
-fun make_bound_var x = bound_var_prefix ^ ascii_of x
-fun make_schematic_var v = schematic_var_prefix ^ ascii_of_indexname v
-fun make_fixed_var x = fixed_var_prefix ^ ascii_of x
-
-fun make_schematic_type_var (x,i) =
-      tvar_prefix ^ (ascii_of_indexname (trim_type_var x,i));
-fun make_fixed_type_var x = tfree_prefix ^ (ascii_of (trim_type_var x));
-
-fun lookup_const c =
-  case Symtab.lookup const_trans_table c of
-    SOME c' => c'
-  | NONE => ascii_of c
-
-(* HOL.eq MUST BE "equal" because it's built into ATPs. *)
-fun make_fixed_const @{const_name HOL.eq} = "equal"
-  | make_fixed_const c = const_prefix ^ lookup_const c
-
-fun make_fixed_type_const c = type_const_prefix ^ lookup_const c
-
-fun make_type_class clas = class_prefix ^ ascii_of clas;
-
-(* The number of type arguments of a constant, zero if it's monomorphic. For
-   (instances of) Skolem pseudoconstants, this information is encoded in the
-   constant name. *)
-fun num_type_args thy s =
-  if String.isPrefix skolem_const_prefix s then
-    s |> space_explode Long_Name.separator |> List.last |> Int.fromString |> the
-  else
-    (s, Sign.the_const_type thy s) |> Sign.const_typargs thy |> length
-
-fun new_skolem_var_from_const s =
-  let
-    val ss = s |> space_explode Long_Name.separator
-    val n = length ss
-  in (nth ss (n - 2), nth ss (n - 3) |> Int.fromString |> the) end
-
-
-(**** Definitions and functions for FOL clauses for TPTP format output ****)
-
-type name = string * string
-
-(**** Isabelle FOL clauses ****)
-
-(* The first component is the type class; the second is a TVar or TFree. *)
-datatype type_literal =
-  TyLitVar of name * name |
-  TyLitFree of name * name
-
-(*Make literals for sorted type variables*)
-fun sorts_on_typs_aux (_, [])   = []
-  | sorts_on_typs_aux ((x,i),  s::ss) =
-      let val sorts = sorts_on_typs_aux ((x,i), ss)
-      in
-          if s = "HOL.type" then sorts
-          else if i = ~1 then TyLitFree (`make_type_class s, `make_fixed_type_var x) :: sorts
-          else TyLitVar (`make_type_class s, (make_schematic_type_var (x,i), x)) :: sorts
-      end;
-
-fun sorts_on_typs (TFree (a,s)) = sorts_on_typs_aux ((a,~1),s)
-  | sorts_on_typs (TVar (v,s))  = sorts_on_typs_aux (v,s);
-
-(*Given a list of sorted type variables, return a list of type literals.*)
-fun type_literals_for_types Ts =
-  fold (union (op =)) (map sorts_on_typs Ts) []
-
-(** make axiom and conjecture clauses. **)
-
-(**** Isabelle arities ****)
-
-datatype arLit =
-  TConsLit of name * name * name list |
-  TVarLit of name * name
-
-datatype arity_clause =
-  ArityClause of {name: string, conclLit: arLit, premLits: arLit list}
-
-
-fun gen_TVars 0 = []
-  | gen_TVars n = ("T_" ^ Int.toString n) :: gen_TVars (n-1);
-
-fun pack_sort(_,[])  = []
-  | pack_sort(tvar, "HOL.type"::srt) = pack_sort (tvar, srt)   (*IGNORE sort "type"*)
-  | pack_sort(tvar, cls::srt) =
-    (`make_type_class cls, (tvar, tvar)) :: pack_sort (tvar, srt)
-
-(*Arity of type constructor tcon :: (arg1,...,argN)res*)
-fun make_axiom_arity_clause (tcons, name, (cls,args)) =
-  let
-    val tvars = gen_TVars (length args)
-    val tvars_srts = ListPair.zip (tvars, args)
-  in
-    ArityClause {name = name,
-                 conclLit = TConsLit (`make_type_class cls,
-                                      `make_fixed_type_const tcons,
-                                      tvars ~~ tvars),
-                 premLits = map TVarLit (union_all (map pack_sort tvars_srts))}
-  end
-
-
-(**** Isabelle class relations ****)
-
-datatype class_rel_clause =
-  ClassRelClause of {name: string, subclass: name, superclass: name}
-
-(*Generate all pairs (sub,super) such that sub is a proper subclass of super in theory thy.*)
-fun class_pairs _ [] _ = []
-  | class_pairs thy subs supers =
-      let
-        val class_less = Sorts.class_less (Sign.classes_of thy)
-        fun add_super sub super = class_less (sub, super) ? cons (sub, super)
-        fun add_supers sub = fold (add_super sub) supers
-      in fold add_supers subs [] end
-
-fun make_class_rel_clause (sub,super) =
-  ClassRelClause {name = sub ^ "_" ^ super,
-                  subclass = `make_type_class sub,
-                  superclass = `make_type_class super}
-
-fun make_class_rel_clauses thy subs supers =
-  map make_class_rel_clause (class_pairs thy subs supers);
-
-
-(** Isabelle arities **)
-
-fun arity_clause _ _ (_, []) = []
-  | arity_clause seen n (tcons, ("HOL.type",_)::ars) =  (*ignore*)
-      arity_clause seen n (tcons,ars)
-  | arity_clause seen n (tcons, (ar as (class,_)) :: ars) =
-      if member (op =) seen class then (*multiple arities for the same tycon, class pair*)
-          make_axiom_arity_clause (tcons, lookup_const tcons ^ "_" ^ class ^ "_" ^ Int.toString n, ar) ::
-          arity_clause seen (n+1) (tcons,ars)
-      else
-          make_axiom_arity_clause (tcons, lookup_const tcons ^ "_" ^ class, ar) ::
-          arity_clause (class::seen) n (tcons,ars)
-
-fun multi_arity_clause [] = []
-  | multi_arity_clause ((tcons, ars) :: tc_arlists) =
-      arity_clause [] 1 (tcons, ars) @ multi_arity_clause tc_arlists
-
-(*Generate all pairs (tycon,class,sorts) such that tycon belongs to class in theory thy
-  provided its arguments have the corresponding sorts.*)
-fun type_class_pairs thy tycons classes =
-  let val alg = Sign.classes_of thy
-      fun domain_sorts tycon = Sorts.mg_domain alg tycon o single
-      fun add_class tycon class =
-        cons (class, domain_sorts tycon class)
-        handle Sorts.CLASS_ERROR _ => I
-      fun try_classes tycon = (tycon, fold (add_class tycon) classes [])
-  in  map try_classes tycons  end;
-
-(*Proving one (tycon, class) membership may require proving others, so iterate.*)
-fun iter_type_class_pairs _ _ [] = ([], [])
-  | iter_type_class_pairs thy tycons classes =
-      let val cpairs = type_class_pairs thy tycons classes
-          val newclasses = union_all (union_all (union_all (map (map #2 o #2) cpairs)))
-            |> subtract (op =) classes |> subtract (op =) HOLogic.typeS
-          val (classes', cpairs') = iter_type_class_pairs thy tycons newclasses
-      in (union (op =) classes' classes, union (op =) cpairs' cpairs) end;
-
-fun make_arity_clauses thy tycons classes =
-  let val (classes', cpairs) = iter_type_class_pairs thy tycons classes
-  in  (classes', multi_arity_clause cpairs)  end;
-
-datatype combtyp =
-  CombTVar of name |
-  CombTFree of name |
-  CombType of name * combtyp list
-
-datatype combterm =
-  CombConst of name * combtyp * combtyp list (* Const and Free *) |
-  CombVar of name * combtyp |
-  CombApp of combterm * combterm
-
-datatype fol_literal = FOLLiteral of bool * combterm
-
-(*********************************************************************)
-(* convert a clause with type Term.term to a clause with type clause *)
-(*********************************************************************)
-
-(*Result of a function type; no need to check that the argument type matches.*)
-fun result_type (CombType (_, [_, tp2])) = tp2
-  | result_type _ = raise Fail "non-function type"
-
-fun combtyp_of (CombConst (_, tp, _)) = tp
-  | combtyp_of (CombVar (_, tp)) = tp
-  | combtyp_of (CombApp (t1, _)) = result_type (combtyp_of t1)
-
-(*gets the head of a combinator application, along with the list of arguments*)
-fun strip_combterm_comb u =
-    let fun stripc (CombApp(t,u), ts) = stripc (t, u::ts)
-        |   stripc  x =  x
-    in stripc(u,[]) end
-
-fun combtype_of (Type (a, Ts)) =
-    let val (folTypes, ts) = combtypes_of Ts in
-      (CombType (`make_fixed_type_const a, folTypes), ts)
-    end
-  | combtype_of (tp as TFree (a, _)) = (CombTFree (`make_fixed_type_var a), [tp])
-  | combtype_of (tp as TVar (x, _)) =
-    (CombTVar (make_schematic_type_var x, string_of_indexname x), [tp])
-and combtypes_of Ts =
-  let val (folTyps, ts) = ListPair.unzip (map combtype_of Ts) in
-    (folTyps, union_all ts)
-  end
-
-(* same as above, but no gathering of sort information *)
-fun simple_combtype_of (Type (a, Ts)) =
-    CombType (`make_fixed_type_const a, map simple_combtype_of Ts)
-  | simple_combtype_of (TFree (a, _)) = CombTFree (`make_fixed_type_var a)
-  | simple_combtype_of (TVar (x, _)) =
-    CombTVar (make_schematic_type_var x, string_of_indexname x)
-
-fun new_skolem_const_name th_no s num_T_args =
-  [new_skolem_const_prefix, string_of_int th_no, s, string_of_int num_T_args]
-  |> space_implode Long_Name.separator
-
-(* Converts a term (with combinators) into a combterm. Also accummulates sort
-   infomation. *)
-fun combterm_from_term thy th_no bs (P $ Q) =
-      let val (P', tsP) = combterm_from_term thy th_no bs P
-          val (Q', tsQ) = combterm_from_term thy th_no bs Q
-      in  (CombApp (P', Q'), union (op =) tsP tsQ)  end
-  | combterm_from_term thy _ _ (Const (c, T)) =
-      let
-        val (tp, ts) = combtype_of T
-        val tvar_list =
-          (if String.isPrefix old_skolem_const_prefix c then
-             [] |> Term.add_tvarsT T |> map TVar
-           else
-             (c, T) |> Sign.const_typargs thy)
-          |> map simple_combtype_of
-        val c' = CombConst (`make_fixed_const c, tp, tvar_list)
-      in  (c',ts)  end
-  | combterm_from_term _ _ _ (Free (v, T)) =
-      let val (tp, ts) = combtype_of T
-          val v' = CombConst (`make_fixed_var v, tp, [])
-      in  (v',ts)  end
-  | combterm_from_term _ th_no _ (Var (v as (s, _), T)) =
-    let
-      val (tp, ts) = combtype_of T
-      val v' =
-        if String.isPrefix Meson_Clausify.new_skolem_var_prefix s then
-          let
-            val tys = T |> strip_type |> swap |> op ::
-            val s' = new_skolem_const_name th_no s (length tys)
-          in
-            CombConst (`make_fixed_const s', tp, map simple_combtype_of tys)
-          end
-        else
-          CombVar ((make_schematic_var v, string_of_indexname v), tp)
-    in (v', ts) end
-  | combterm_from_term _ _ bs (Bound j) =
-      let
-        val (s, T) = nth bs j
-        val (tp, ts) = combtype_of T
-        val v' = CombConst (`make_bound_var s, tp, [])
-      in (v', ts) end
-  | combterm_from_term _ _ _ (Abs _) = raise Fail "HOL clause: Abs"
-
-fun predicate_of thy th_no ((@{const Not} $ P), pos) =
-    predicate_of thy th_no (P, not pos)
-  | predicate_of thy th_no (t, pos) =
-    (combterm_from_term thy th_no [] (Envir.eta_contract t), pos)
-
-fun literals_of_term1 args thy th_no (@{const Trueprop} $ P) =
-    literals_of_term1 args thy th_no P
-  | literals_of_term1 args thy th_no (@{const HOL.disj} $ P $ Q) =
-    literals_of_term1 (literals_of_term1 args thy th_no P) thy th_no Q
-  | literals_of_term1 (lits, ts) thy th_no P =
-    let val ((pred, ts'), pol) = predicate_of thy th_no (P, true) in
-      (FOLLiteral (pol, pred) :: lits, union (op =) ts ts')
-    end
-val literals_of_term = literals_of_term1 ([], [])
-
-fun old_skolem_const_name i j num_T_args =
-  old_skolem_const_prefix ^ Long_Name.separator ^
-  (space_implode Long_Name.separator (map Int.toString [i, j, num_T_args]))
-
-fun conceal_old_skolem_terms i old_skolems t =
-  if exists_Const (curry (op =) @{const_name skolem} o fst) t then
-    let
-      fun aux old_skolems
-              (t as (Const (@{const_name skolem}, Type (_, [_, T])) $ _)) =
-          let
-            val (old_skolems, s) =
-              if i = ~1 then
-                (old_skolems, @{const_name undefined})
-              else case AList.find (op aconv) old_skolems t of
-                s :: _ => (old_skolems, s)
-              | [] =>
-                let
-                  val s = old_skolem_const_name i (length old_skolems)
-                                                (length (Term.add_tvarsT T []))
-                in ((s, t) :: old_skolems, s) end
-          in (old_skolems, Const (s, T)) end
-        | aux old_skolems (t1 $ t2) =
-          let
-            val (old_skolems, t1) = aux old_skolems t1
-            val (old_skolems, t2) = aux old_skolems t2
-          in (old_skolems, t1 $ t2) end
-        | aux old_skolems (Abs (s, T, t')) =
-          let val (old_skolems, t') = aux old_skolems t' in
-            (old_skolems, Abs (s, T, t'))
-          end
-        | aux old_skolems t = (old_skolems, t)
-    in aux old_skolems t end
-  else
-    (old_skolems, t)
-
-fun reveal_old_skolem_terms old_skolems =
-  map_aterms (fn t as Const (s, _) =>
-                 if String.isPrefix old_skolem_const_prefix s then
-                   AList.lookup (op =) old_skolems s |> the
-                   |> map_types Type_Infer.paramify_vars
-                 else
-                   t
-               | t => t)
-
-
-(***************************************************************)
-(* Type Classes Present in the Axiom or Conjecture Clauses     *)
-(***************************************************************)
-
-fun set_insert (x, s) = Symtab.update (x, ()) s
-
-fun add_classes (sorts, cset) = List.foldl set_insert cset (flat sorts)
-
-(*Remove this trivial type class*)
-fun delete_type cset = Symtab.delete_safe (the_single @{sort HOL.type}) cset;
-
-fun tfree_classes_of_terms ts =
-  let val sorts_list = map (map #2 o OldTerm.term_tfrees) ts
-  in  Symtab.keys (delete_type (List.foldl add_classes Symtab.empty sorts_list))  end;
-
-fun tvar_classes_of_terms ts =
-  let val sorts_list = map (map #2 o OldTerm.term_tvars) ts
-  in  Symtab.keys (delete_type (List.foldl add_classes Symtab.empty sorts_list))  end;
-
-(*fold type constructors*)
-fun fold_type_consts f (Type (a, Ts)) x = fold (fold_type_consts f) Ts (f (a,x))
-  | fold_type_consts _ _ x = x;
-
-(*Type constructors used to instantiate overloaded constants are the only ones needed.*)
-fun add_type_consts_in_term thy =
-  let
-    fun aux (Const x) =
-        fold (fold_type_consts set_insert) (Sign.const_typargs thy x)
-      | aux (Abs (_, _, u)) = aux u
-      | aux (Const (@{const_name skolem}, _) $ _) = I
-      | aux (t $ u) = aux t #> aux u
-      | aux _ = I
-  in aux end
-
-fun type_consts_of_terms thy ts =
-  Symtab.keys (fold (add_type_consts_in_term thy) ts Symtab.empty);
-
-(* ------------------------------------------------------------------------- *)
-(* HOL to FOL  (Isabelle to Metis)                                           *)
-(* ------------------------------------------------------------------------- *)
-
-datatype mode = FO | HO | FT  (* first-order, higher-order, fully-typed *)
-
-fun string_of_mode FO = "FO"
-  | string_of_mode HO = "HO"
-  | string_of_mode FT = "FT"
-
-fun fn_isa_to_met_sublevel "equal" = "=" (* FIXME: "c_fequal" *)
-  | fn_isa_to_met_sublevel x = x
-fun fn_isa_to_met_toplevel "equal" = "="
-  | fn_isa_to_met_toplevel x = x
-
-fun metis_lit b c args = (b, (c, args));
-
-fun metis_term_from_combtyp (CombTVar (s, _)) = Metis_Term.Var s
-  | metis_term_from_combtyp (CombTFree (s, _)) = Metis_Term.Fn (s, [])
-  | metis_term_from_combtyp (CombType ((s, _), tps)) =
-    Metis_Term.Fn (s, map metis_term_from_combtyp tps);
-
-(*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 strip_combterm_comb tm of
-      (CombConst ((c, _), _, tys), tms) =>
-        let val tyargs = map metis_term_from_combtyp tys
-            val args   = map hol_term_to_fol_FO tms
-        in Metis_Term.Fn (c, tyargs @ args) end
-    | (CombVar ((v, _), _), []) => Metis_Term.Var v
-    | _ => raise Fail "non-first-order combterm"
-
-fun hol_term_to_fol_HO (CombConst ((a, _), _, tylist)) =
-      Metis_Term.Fn (fn_isa_to_met_sublevel a, map metis_term_from_combtyp tylist)
-  | hol_term_to_fol_HO (CombVar ((s, _), _)) = Metis_Term.Var s
-  | hol_term_to_fol_HO (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 (type_wrapper_name, [tm, metis_term_from_combtyp ty])
-
-fun hol_term_to_fol_FT (CombVar ((s, _), ty)) = wrap_type (Metis_Term.Var s, ty)
-  | hol_term_to_fol_FT (CombConst((a, _), ty, _)) =
-      wrap_type (Metis_Term.Fn(fn_isa_to_met_sublevel a, []), ty)
-  | hol_term_to_fol_FT (tm as CombApp(tm1,tm2)) =
-       wrap_type (Metis_Term.Fn(".", map hol_term_to_fol_FT [tm1,tm2]),
-                  combtyp_of tm)
-
-fun hol_literal_to_fol FO (FOLLiteral (pos, tm)) =
-      let val (CombConst((p, _), _, tys), tms) = strip_combterm_comb tm
-          val tylits = if p = "equal" then [] else map metis_term_from_combtyp tys
-          val lits = map hol_term_to_fol_FO tms
-      in metis_lit pos (fn_isa_to_met_toplevel p) (tylits @ lits) end
-  | hol_literal_to_fol HO (FOLLiteral (pos, tm)) =
-     (case strip_combterm_comb tm of
-          (CombConst(("equal", _), _, _), tms) =>
-            metis_lit pos "=" (map hol_term_to_fol_HO tms)
-        | _ => metis_lit pos "{}" [hol_term_to_fol_HO tm])   (*hBOOL*)
-  | hol_literal_to_fol FT (FOLLiteral (pos, tm)) =
-     (case strip_combterm_comb tm of
-          (CombConst(("equal", _), _, _), tms) =>
-            metis_lit pos "=" (map hol_term_to_fol_FT tms)
-        | _ => metis_lit pos "{}" [hol_term_to_fol_FT tm])   (*hBOOL*);
-
-fun literals_of_hol_term thy th_no mode t =
-      let val (lits, types_sorts) = literals_of_term thy th_no 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_type_literals pos (TyLitVar ((s, _), (s', _))) =
-    metis_lit pos s [Metis_Term.Var s']
-  | metis_of_type_literals pos (TyLitFree ((s, _), (s', _))) =
-    metis_lit pos s [Metis_Term.Fn (s',[])]
-
-fun default_sort _ (TVar _) = false
-  | default_sort ctxt (TFree (x, s)) = (s = the_default [] (Variable.def_sort ctxt (x, ~1)));
-
-fun metis_of_tfree tf =
-  Metis_Thm.axiom (Metis_LiteralSet.singleton (metis_of_type_literals true tf));
-
-fun hol_thm_to_fol is_conjecture th_no ctxt type_lits mode j old_skolems th =
-  let
-    val thy = ProofContext.theory_of ctxt
-    val (old_skolems, (mlits, types_sorts)) =
-     th |> prop_of |> Logic.strip_imp_concl
-        |> conceal_old_skolem_terms j old_skolems
-        ||> (HOLogic.dest_Trueprop #> literals_of_hol_term thy th_no mode)
-  in
-    if is_conjecture then
-      (Metis_Thm.axiom (Metis_LiteralSet.fromList mlits),
-       type_literals_for_types types_sorts, old_skolems)
-    else
-      let
-        val tylits = filter_out (default_sort ctxt) types_sorts
-                     |> type_literals_for_types
-        val mtylits =
-          if type_lits then map (metis_of_type_literals false) tylits else []
-      in
-        (Metis_Thm.axiom (Metis_LiteralSet.fromList(mtylits @ mlits)), [],
-         old_skolems)
-      end
-  end;
-
-val helpers =
-  [("c_COMBI", (false, map (`I) @{thms COMBI_def})),
-   ("c_COMBK", (false, map (`I) @{thms COMBK_def})),
-   ("c_COMBB", (false, map (`I) @{thms COMBB_def})),
-   ("c_COMBC", (false, map (`I) @{thms COMBC_def})),
-   ("c_COMBS", (false, map (`I) @{thms COMBS_def})),
-   ("c_fequal", (false, map (rpair @{thm equal_imp_equal})
-                            @{thms fequal_imp_equal equal_imp_fequal})),
-   ("c_True", (true, map (`I) @{thms True_or_False})),
-   ("c_False", (true, map (`I) @{thms True_or_False})),
-   ("c_If", (true, map (`I) @{thms if_True if_False True_or_False}))]
-
-(* ------------------------------------------------------------------------- *)
-(* Logic maps manage the interface between HOL and first-order logic.        *)
-(* ------------------------------------------------------------------------- *)
-
-type logic_map =
-  {axioms: (Metis_Thm.thm * thm) list,
-   tfrees: type_literal list,
-   old_skolems: (string * term) list}
-
-fun is_quasi_fol_clause thy =
-  Meson.is_fol_term thy o snd o conceal_old_skolem_terms ~1 [] o prop_of
-
-(*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
-    Vartab.fold add (#2 (Variable.constraints_of ctxt)) []
-    |> type_literals_for_types
-  end;
-
-(*Insert non-logical axioms corresponding to all accumulated TFrees*)
-fun add_tfrees {axioms, tfrees, old_skolems} : logic_map =
-     {axioms = map (rpair TrueI o metis_of_tfree) (distinct (op =) tfrees) @
-               axioms,
-      tfrees = tfrees, old_skolems = old_skolems}
-
-(*transform isabelle type / arity clause to metis clause *)
-fun add_type_thm [] lmap = lmap
-  | add_type_thm ((ith, mth) :: cls) {axioms, tfrees, old_skolems} =
-      add_type_thm cls {axioms = (mth, ith) :: axioms, tfrees = tfrees,
-                        old_skolems = old_skolems}
-
-fun const_in_metis c (pred, tm_list) =
-  let
-    fun in_mterm (Metis_Term.Var _) = 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;
-
-(* ARITY CLAUSE *)
-fun m_arity_cls (TConsLit ((c, _), (t, _), args)) =
-    metis_lit true c [Metis_Term.Fn(t, map (Metis_Term.Var o fst) args)]
-  | m_arity_cls (TVarLit ((c, _), (s, _))) =
-    metis_lit false c [Metis_Term.Var s]
-(*TrueI is returned as the Isabelle counterpart because there isn't any.*)
-fun arity_cls (ArityClause {conclLit, premLits, ...}) =
-  (TrueI,
-   Metis_Thm.axiom (Metis_LiteralSet.fromList (map m_arity_cls (conclLit :: premLits))));
-
-(* CLASSREL CLAUSE *)
-fun m_class_rel_cls (subclass, _) (superclass, _) =
-  [metis_lit false subclass [Metis_Term.Var "T"], metis_lit true superclass [Metis_Term.Var "T"]];
-fun class_rel_cls (ClassRelClause {subclass, superclass, ...}) =
-  (TrueI, Metis_Thm.axiom (Metis_LiteralSet.fromList (m_class_rel_cls subclass superclass)));
-
-fun type_ext thy tms =
-  let val subs = tfree_classes_of_terms tms
-      val supers = tvar_classes_of_terms tms
-      and tycons = type_consts_of_terms thy tms
-      val (supers', arity_clauses) = make_arity_clauses thy tycons supers
-      val class_rel_clauses = make_class_rel_clauses thy subs supers'
-  in  map class_rel_cls class_rel_clauses @ map arity_cls arity_clauses
-  end;
-
-(* Function to generate metis clauses, including comb and type clauses *)
-fun build_logic_map mode0 ctxt type_lits cls thss =
-  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 (forall (is_quasi_fol_clause thy)) (cls :: thss) then FO
-          else HO
-        | set_mode FT = FT
-      val mode = set_mode mode0
-      (*transform isabelle clause to metis clause *)
-      fun add_thm th_no is_conjecture (metis_ith, isa_ith)
-                  {axioms, tfrees, old_skolems} : logic_map =
-        let
-          val (mth, tfree_lits, old_skolems) =
-            hol_thm_to_fol is_conjecture th_no ctxt type_lits mode (length axioms)
-                           old_skolems metis_ith
-        in
-           {axioms = (mth, Meson.make_meta_clause isa_ith) :: axioms,
-            tfrees = union (op =) tfree_lits tfrees, old_skolems = old_skolems}
-        end;
-      val lmap = {axioms = [], tfrees = init_tfrees ctxt, old_skolems = []}
-                 |> fold (add_thm 0 true o `I) cls
-                 |> add_tfrees
-                 |> fold (fn (th_no, ths) => fold (add_thm th_no false o `I) ths)
-                         (1 upto length thss ~~ thss)
-      val clause_lists = map (Metis_Thm.clause o #1) (#axioms lmap)
-      fun is_used c =
-        exists (Metis_LiteralSet.exists (const_in_metis c o #2)) clause_lists
-      val lmap =
-        if mode = FO then
-          lmap
-        else
-          let
-            val helper_ths =
-              helpers |> filter (is_used o fst)
-                      |> maps (fn (c, (needs_full_types, thms)) =>
-                                  if not (is_used c) orelse
-                                     needs_full_types andalso mode <> FT then
-                                    []
-                                  else
-                                    thms)
-          in lmap |> fold (add_thm ~1 false) helper_ths end
-  in
-    (mode, add_type_thm (type_ext thy (maps (map prop_of) (cls :: thss))) lmap)
-  end
-
-end;
--- a/src/HOL/Tools/Sledgehammer/sledgehammer_filter.ML	Mon Oct 04 22:01:34 2010 +0200
+++ b/src/HOL/Tools/Sledgehammer/sledgehammer_filter.ML	Mon Oct 04 22:45:09 2010 +0200
@@ -585,6 +585,7 @@
 fun is_formula_too_complex t =
   apply_depth t > max_apply_depth orelse formula_has_too_many_lambdas [] t
 
+(* FIXME: Extend to "Meson" and "Metis" *)
 val exists_sledgehammer_const =
   exists_Const (fn (s, _) => String.isPrefix sledgehammer_prefix s)