# Module Sig.G.V

    module V: Sig.VERTEX

Vertices have type `V.t` and are labeled with type `V.label` (note that an implementation may identify the vertex with its label)

Vertices are `Sig.COMPARABLE`.

    type t

    val compare : t -> t -> int

    val hash : t -> int

    val equal : t -> t -> bool

Vertices are labeled.

    type label

    val create : label -> t

    val label : t -> label