Let G be a graph with vertex set V (G) and edge set E(G). For u ? V (G), NV (u) = {w ? V (G)|uw ? E(G)} and NE(u) = {e ? E(G)|e = uv, for some v ? V (G)}. A bijective function f : V (G) ? E(G) ? {1, 2, 3, . . . , |V (G) ? ...