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 :
val merge_subst_if_possible:
substitution -> substitution ->
substitution option
-val concat_substs: substitution -> substitution -> substitution
-
+val concat: substitution -> substitution -> substitution