let nparamod metasenv subst context t table =
  prerr_endline "========================================";
  let module C = struct
    let metasenv = metasenv
    let subst = subst
    let context = context
  end
  in
  let module B = NCicBlob.NCicBlob(C) in
  let module Pp = Pp.Pp (B) in
  let module FU = FoUnif.Founif(B) in
  let module IDX = Index.Index(B) in
  let module Sup = Superposition.Superposition(B) in
  let module Utils = FoUtils.Utils(B) in
(*
  let test_unification _ = function
    | Terms.Node [_; _; lhs; rhs] ->
	prerr_endline "Unification test :";
	prerr_endline (Pp.pp_foterm lhs);
	prerr_endline (Pp.pp_foterm rhs);
        FU.unification [] [] lhs rhs
    | _ -> assert false
  in
  let subst,vars = test_unification [] res in
    prerr_endline "Result :";
    prerr_endline (Pp.pp_foterm res);
    prerr_endline "Substitution :";
    prerr_endline (Pp.pp_substitution subst)
*)
  let mk_clause maxvar t =
    let ty = B.embed t in
    let proof = B.embed (NCic.Rel ~-1) in
    Utils.mk_unit_clause maxvar ty proof 
  in
  let clause, maxvar = mk_clause 0 t in
  prerr_endline "Input clause :";
  prerr_endline (Pp.pp_unit_clause clause);
  let bag = Utils.empty_bag in
  let active_clauses, maxvar = 
    List.fold_left
      (fun (cl,maxvar) t -> 
         let c, m = mk_clause maxvar t in
         c::cl, m)
      ([],maxvar) table 
  in
  let table =  
    List.fold_left IDX.index_unit_clause IDX.DT.empty active_clauses
  in
  prerr_endline "Active table:";
  List.iter (fun uc -> prerr_endline (Pp.pp_unit_clause uc)) active_clauses;
  let bag, maxvar, _, newclauses = 
    Sup.infer_right bag maxvar clause (active_clauses, table)
  in
  prerr_endline "Output clauses :";
  List.iter (fun c -> prerr_endline (Pp.pp_unit_clause c)) newclauses;
  prerr_endline "Proofs: ";
  prerr_endline (Pp.pp_bag bag);
  prerr_endline "========================================";
;;

let select = function 
  | [] -> None
  | x::tl -> Some (x, tl)
;;

let nparamod metasenv subst context t table =
  prerr_endline "========================================";
  let module C = struct
    let metasenv = metasenv
    let subst = subst
    let context = context
  end
  in
  let module B = NCicBlob.NCicBlob(C) in
  let module Pp = Pp.Pp (B) in
  let module FU = FoUnif.Founif(B) in
  let module IDX = Index.Index(B) in
  let module Sup = Superposition.Superposition(B) in
  let module Utils = FoUtils.Utils(B) in

  let rec given_clause bag maxvar actives passives g_actives g_passives =

    (* keep goals demodulated w.r.t. actives and check if solved *)
    (* we may move this at the end of infer_right and simplify with
     * just new_clauses *) 
    let bag, g_actives = 
      List.fold_left 
        (fun (bag,acc) c -> 
          let bag, c = Sup.backward_simplify maxvar (snd actives) bag c in
          bag, c::acc) 
        (bag,[]) g_actives 
    in

    (* backward step *)
    let bag, maxvar, g_actives, g_passives =
      match select g_passives with
      | None -> bag, maxvar, g_actives, g_passives
      | Some (g_current, g_passives) -> 
          let bag, g_current = 
            Sup.backward_simplify maxvar (snd actives) bag g_current
          in
          let bag, maxvar, new_goals = 
            Sup.infer_left bag maxvar g_current actives 
          in
          bag, maxvar, g_current::g_actives, g_passives @ new_goals
    in
  
    (* forward step *)
    let bag, maxvar, actives, passives =
      match select passives with
      | None -> bag, maxvar, actives, passives
      | Some (current, passives) -> 
          match Sup.forward_simplify (snd actives) bag current with
          | None -> bag, maxvar, actives, passives
          | Some (bag, current) ->
              let bag, maxvar, actives, new_clauses = 
                Sup.infer_right bag maxvar current actives 
              in
              bag, maxvar, actives, passives @ new_clauses
    in

      given_clause bag maxvar actives passives g_actives g_passives
  in

  let mk_clause bag maxvar ty =
    let ty = B.embed ty in
    let proof = B.embed (NCic.Rel ~-1) in
    let c, maxvar = Utils.mk_unit_clause maxvar ty proof in
    let bag, c = Utils.add_to_bag bag c in
    bag, maxvar, c
  in
  let bag, maxvar, goal = mk_clause Terms.M.empty 0 t in
  let g_actives = [] in
  let g_passives = [goal] in
  let passives, bag, maxvar = 
    List.fold_left
      (fun (cl, bag, maxvar) t -> 
         let bag, maxvar, c = mk_clause bag maxvar t in
         c::cl, bag, maxvar)
      ([], bag, maxvar) table 
  in
  let actives = [], IDX.DT.empty in
  try given_clause bag maxvar actives passives g_actives g_passives
  with Sup.Success _ -> prerr_endline "YES!"
;;