* http://cs.unibo.it/helm/.
*)
+exception CannotSubstInMeta;;
+exception RelToHiddenHypothesis;;
+exception ReferenceToVariable;;
+exception ReferenceToConstant;;
+exception ReferenceToInductiveDefinition;;
+exception DeliftingWouldCaptureAFreeVariable;;
+
+(* lift n t *)
+(* lifts [t] of [n] *)
val lift : int -> Cic.term -> Cic.term
+
+(** delifts t of n
+ * @raise Failure s
+ *)
+val delift : 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] *)
val subst : Cic.term -> Cic.term -> Cic.term
-val lift_meta : (Cic.term option) list -> Cic.term -> Cic.term
-val undebrujin_inductive_def : UriManager.uri -> Cic.obj -> Cic.obj
+
+(* 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
+