Make_Imperative.NSet
type t
type elt = N.t
val iter : (NSet.elt -> unit) -> NSet.t -> unit
val mem : NSet.t -> NSet.elt -> bool
val add : NSet.t -> NSet.elt -> unit
val remove : NSet.t -> NSet.elt -> unit
val copy : NSet.t -> NSet.t