${\mathbb{Z}}_2^2$-cordiality of complete and complete bipartite graphs

Abstract

We prove that $K_n$ is ${\mathbb{Z}}_2^2$-cordial if and only if $1\le n\le 3$ and that $K_{m,n}$ is ${\mathbb{Z}}_2^2$ if and only if it is false that $m=n=2$.

4 pages