include G
val iter_succ : ( V.t -> unit ) -> t -> V.t -> unitval fold_succ : ( V.t -> 'a -> 'a ) -> t -> V.t -> 'a -> 'aval iter_vertex : ( V.t -> unit ) -> t -> unitval fold_vertex : ( V.t -> 'a -> 'a ) -> t -> 'a -> 'aval remove_vertex : t -> V.t -> t