type t = Graph__Imperative.Digraph.Concrete(PkgV).t
val out_degree : t -> vertex -> int
val mem_vertex : t -> vertex -> bool
val mem_edge_e : t -> edge -> bool
val iter_vertex : (vertex -> unit) -> t -> unit
val fold_vertex : (vertex -> 'a -> 'a) -> t -> 'a -> 'a
val iter_edges_e : (edge -> unit) -> t -> unit
val fold_edges_e : (edge -> 'a -> 'a) -> t -> 'a -> 'a
val iter_succ_e : (edge -> unit) -> t -> vertex -> unit
val fold_succ_e : (edge -> 'a -> 'a) -> t -> vertex -> 'a -> 'a
val iter_pred_e : (edge -> unit) -> t -> vertex -> unit
val fold_pred_e : (edge -> 'a -> 'a) -> t -> vertex -> 'a -> 'a
val create : ?size:int -> unit -> t
val add_vertex : t -> vertex -> unit
val remove_vertex : t -> vertex -> unit
val add_edge_e : t -> edge -> unit
val remove_edge_e : t -> edge -> unit