Definition:Edgeless Graph

A null graph is a graph with no edges.

The null graph of order $n$ is denoted $$N_n$$.

By definition, all vertices of a null graph are isolated.

Basic Properties

 * The null graph $$N_n$$ is $0$-regular for all $$n$$.


 * The null graph $$N_n$$ is (vacuously) bipartite for all $$n$$.


 * The null graph $$N_n$$ has $$n$$ components for all $$n$$.


 * $$N_1$$ is the complete graph $$K_1$$ and also the path graph $$P_1$$.