3-PRODUCT CORDIAL LABELING OF THE UNION OF A TREE AND A CYCLE
Let G be a graph. A mapping is called a 3-product cordial labeling of G if and for any where denotes the number of vertices x with and denotes the number of edges xy with We show that every tree has a 3-product cordial labeling. We also show that the union G of a tree and a cycle has a 3-product cordial labeling unless G is one of some exceptional graphs.
3-product cordial labeling, 3-product cordial graph.