Fig. 3. Primal (left) and dual (right) networks for a square lattice.

In this example, the lattice has N = 8 routes. Each route has k = N/2 = 4 connections, so the total number of connections is K_tot = k² = 16. In the dual network, the four east–west routes (A to D) and the four north–south routes (E to H) yield a graph with a diameter of 2.