(*
    ||M||  This file is part of HELM, an Hypertextual, Electronic        
    ||A||  Library of Mathematics, developed at the Computer Science     
    ||T||  Department, University of Bologna, Italy.                     
    ||I||                                                                
    ||T||  HELM is free software; you can redistribute it and/or         
    ||A||  modify it under the terms of the GNU General Public License   
    \   /  version 2 or (at your option) any later version.      
     \ /   This software is distributed as is, NO WARRANTY.     
      V_______________________________________________________________ *)

(* $Id$ *)

type path_string

val pp_path_string : path_string -> string

module DiscriminationTreeIndexing :
  functor (A : Set.S) ->
    sig

      type t 
      val iter : t -> (path_string -> A.t -> unit) -> unit

      val empty : t
      val index : t -> NCic.term -> A.elt -> t
      val remove_index : t -> NCic.term -> A.elt -> t
      val in_index : t -> NCic.term -> (A.elt -> bool) -> bool
      val retrieve_generalizations : t -> NCic.term -> A.t
      val retrieve_unifiables : t -> NCic.term -> A.t
    end