“…Node i Node j Arcs (i, j) (3,5), (3,6), (3,7), (4,5), (4,6),(4,7),(5,6),(5,7)} 3 5 9 {(5,9),(6,9),(7,9),(8,9)} Table 2 Arcs associated to the graph of figure 1 If we consider the sequence of arcs (path) defined by {(1, 4), (4, 7)e(7, 9)}, the first strata would be defined by the indexes from 1 to 3, the second would have the indexes from 4 to 6 and the third, the indexes 7 and 8.…”