# What does this mean? $K_n \boxtimes K_n$

I have to show that $K_n \boxtimes K_n = K_{n^2}$. Where $K_n$ is a complete graph. What does the operator "$\boxtimes$" do?

• When you have a question about notation like that, it's a good idea to say where you found it... – Najib Idrissi Mar 11 '14 at 12:44

The strong product of $G$ and $H$ is the graph denoted as $G \boxtimes H$, and defined by
$$V(G\boxtimes H) = \{(g,h) | g \in V(G) \text{ and } \in V(H) \}.$$ $$E(G\boxtimes H) = E(G\square H) \cup E(G\times H).$$