New classes of graphs with edge $\delta -$ graceful labeling

Graph labeling is a source of valuable mathematical models for an extensive range of applications in technologies (communication networks, cryptography, astronomy, data security, various coding theory problems). An edge $\delta -$ graceful labeling of a graph $G$ with $p$ vertices and $q$ edges, for any positive integer $\delta$, is a bijective $f$ from the set of edge $E(G)$ to the set of positive integers $\{\delta ,2\delta ,3\delta ,\cdots ,q\delta \}$ such that all the vertex labels $f^{\ast }[V(G)]$, given by: $f^{\ast }(u)=({\sum }_{uv\in E(G)}f(uv))mod(\delta k)$, where $k=max(p,q)$, are pairwise distinct. In this paper, we show the existence of an edge $\delta -$ graceful labeling, for any positive integer $\delta$, for the following graphs: the splitting graphs of the cycle, fan, and crown, the shadow graphs of the path, cycle, and fan graph, the middle graphs and the total graphs of the path, cycle, and crown. Finally, we display the existence of an edge $\delta -$ graceful labeling, for the twig and snail graphs.