--- /dev/null
+(* Copyright (C) 2006, 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/
+ *)
+
+type substitution
+
+val empty_subst : substitution
+val apply_subst : substitution -> Cic.term -> Cic.term
+val apply_subst_lift : int -> substitution -> Cic.term -> Cic.term
+val apply_subst_metasenv : substitution -> Cic.metasenv -> Cic.metasenv
+val ppsubst : ?names:(Cic.name option list) -> substitution -> string
+val buildsubst :
+ int -> Cic.context -> Cic.term -> Cic.term -> substitution ->
+ substitution
+val flatten_subst : substitution -> substitution
+val lookup_subst : Cic.term -> substitution -> Cic.term
+val filter : substitution -> Cic.metasenv -> Cic.metasenv
+val is_in_subst : int -> substitution -> bool
+val merge_subst_if_possible:
+ substitution -> substitution ->
+ substitution option
+val concat: substitution -> substitution -> substitution