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+(* Copyright (C) 2005, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+module type EqualityIndex =
+ sig
+ module PosEqSet : Set.S with type elt = Utils.pos * Inference.equality
+ val arities : (Cic.term, int) Hashtbl.t
+ type key = Cic.term
+ type t = Discrimination_tree.DiscriminationTreeIndexing(PosEqSet).t
+ val empty : t
+ val retrieve_generalizations : t -> key -> PosEqSet.t
+ val retrieve_unifiables : t -> key -> PosEqSet.t
+ val init_index : unit -> unit
+ val remove_index : t -> Inference.equality -> t
+ val index : t -> Inference.equality -> t
+ val in_index : t -> Inference.equality -> bool
+ end
+
+module DT : EqualityIndex
+module PT : EqualityIndex
+