Directed path graphs

The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\overrightarrow P_k(D)$ of a digraph D is obtained by representing the directed paths on k vertices of D by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in D form a directed path on k + 1 vertices or form a directed cycle on k vertices in D. Several properties of $\overrightarrow P_k(D)$ are studied, in particular with respect to isomorphism and traversability