Edge δ - Graceful Labeling for Some Cyclic-Related Graphs

In this paper, we introduce a new type of labeling of a graph G with p vertices and q edges called edge δ- graceful labeling, for any positive integer δ, as a bijective mapping f of the edge set EG into the set δ,2δ,3δ,⋯,qδ such that the induced mapping f∗:VG→0,δ,2δ,3δ,⋯,qδ-δ, given by f∗u=EGfuvmodδk, where k=maxp,q, is an injective function. We prove the existence of an edge δ- graceful labeling, for any positive integer δ, for some cycle-related graphs like the wheel graph, alternate triangular cycle, double wheel graph Wn,n, the prism graph Πn, the prism of the wheel PWn, the gear graph Gn, the closed helm CHn, the butterfly graph Bn, and the friendship Frn. © 2020 Elsevier B.V., All rights reserved.