Graphs without gap-vertex-labellings: families and bounds

C. A. Weffort-Santos, R. C. S. Schouery

A proper labelling of a graph $G$ is a pair $(\pi ,c_{\pi })$ in which $\pi$ is an assignment of numeric labels to some elements of $G$, and $c_{\pi }$ is a colouring induced by $\pi$ through some…