occasionally referred to as a null graph in contexts where the order-zero graph is not permitted. It is a 0-regular graph. The notation arises from the fact that the -vertex edgeless graph is the complement of the complete graph . See also Glossary of graph theory Cycle graph Path graph Notes References Harary, F. and Read, R. (1973), "Is the null graph a pointless concept?", Graphs and Combinatorics (Conference, George Washington University), Springer-Verlag, New York, NY. Graph families Regular graphs