“…We know that a simple graph G = (V, E) is an ordered pair consisting of a set of vertices V = {v 1 , v 2 , ..., v n } and a set of undirected edges E = {e 1 , e 2 , ..., e n }, no loops nor multiple edges permitted [49,50]. A mixed graph G = (V, E, A) is an ordered triple consisting of a set of vertices V = v 1 , v 2 , ..., v n , a set of undirected edges E = {e 1 , e 2 , ..., e n }, and a set of directed arcs A [51].…”