Fig. 1
Temporal digraph of the DCN \(\mathcal {C} := \{(1,4,\tau _{1}), (5,4,\tau _{2}), (2,5,\tau _{3}), (4,3,\tau _{4})\}\) with Ï„1<Ï„2<Ï„3<Ï„4. We indicate a temporally coherent path from \(\mathcal {C}\)-vertices 1 to 3 with bold versus gray arrows: note that there is no temporally coherent path from 2 to 3. In the figure, spatial (respectively, temporal) arcs are vertical (horizontal). The vertices along a horizontal path constitute the temporal fiber \(\mathcal {C}@v\) for v