# Module type Coloring.GM

    module type GM = sig .. end

Minimal graph signature for `Coloring.GM.Mark`. Sub-signature of `Sig.IM`.

    val is_directed : bool

    type t

    val nb_vertex : t -> int

    module V: Sig.COMPARABLE

    val out_degree : t -> V.t -> int

    val iter_vertex : (V.t -> unit) -> t -> unit

    val fold_vertex : (V.t -> 'a -> 'a) -> t -> 'a -> 'a

    val iter_succ : (V.t -> unit) -> t -> V.t -> unit

    val fold_succ : (V.t -> 'a -> 'a) -> t -> V.t -> 'a -> 'a

    module Mark: sig .. end