sig
type subs
val empty : Subs.subs
val is_empty : Subs.subs -> bool
val subs : Var.var -> Term.term -> Subs.subs
val add : Var.var -> Term.term -> Subs.subs -> Subs.subs
val check_add : Var.var -> Term.term -> Subs.subs -> Subs.subs
val find : Var.var -> Subs.subs -> Term.term
val mem : Var.var -> Subs.subs -> bool
val map : (Term.term -> Term.term) -> Subs.subs -> Subs.subs
val apply : Subs.subs -> Term.term -> Term.term
val domain : Subs.subs -> Var.VarSet.t
val restrict : Subs.subs -> Var.VarSet.t -> Subs.subs
val comp : Subs.subs -> Subs.subs -> Subs.subs
val comp_res : Subs.subs -> Subs.subs -> Subs.subs
val inverse : Subs.subs -> Subs.subs
val fprintf : Format.formatter -> Subs.subs -> unit
end