--- /dev/null
+(* Copyright (C) 2000, 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://cs.unibo.it/helm/.
+ *)
+
+exception CannotSubstInMeta;;
+exception RelToHiddenHypothesis;;
+exception ReferenceToVariable;;
+exception ReferenceToConstant;;
+exception ReferenceToInductiveDefinition;;
+
+(* lift n t *)
+(* lifts [t] of [n] *)
+(* NOTE: the opposite function (delift_rels) is defined in CicMetaSubst *)
+(* since it needs to restrict the metavariables in case of failure *)
+val lift : int -> Cic.term -> Cic.term
+
+
+(* lift from n t *)
+(* as lift but lifts only indexes >= from *)
+val lift_from: int -> int -> Cic.term -> Cic.term
+
+(* subst t1 t2 *)
+(* substitutes [t1] for [Rel 1] in [t2] *)
+(* if avoid_beta_redexes is true (default: false) no new beta redexes *)
+(* are generated. WARNING: the substitution can diverge when t2 is not *)
+(* well typed and avoid_beta_redexes is true. *)
+val subst : ?avoid_beta_redexes:bool -> Cic.term -> Cic.term -> Cic.term
+
+(* subst_vars exp_named_subst t2 *)
+(* applies [exp_named_subst] to [t2] *)
+val subst_vars :
+ Cic.term Cic.explicit_named_substitution -> Cic.term -> Cic.term
+
+(* subst_meta [t_1 ; ... ; t_n] t *)
+(* returns the term [t] where [Rel i] is substituted with [t_i] *)
+(* [t_i] is lifted as usual when it crosses an abstraction *)
+val subst_meta : (Cic.term option) list -> Cic.term -> Cic.term
+