Figure 3.

Example of construction of the canonical form. Node a has the highest degree (2), so a is the first node of the ordering. Nodes b and c have the same degree, so we need to examine the adjacency lists of b and c sorted by timestamp and destination node. The first edge in the sorted list of b has timestamp 1, while the first edge in the sorted list of c has timestamp 2, so the second node of the ordering is b and the third one is c. Following such node ordering, the canonical form of the graph in the figure is {(a, 1, b), (a, 2, c), (b, 1, a), (c, 2, a)}.