FURTHER RESULTS ON PAIR MEAN CORDIAL GRAPHS

Let a graph G = (V, E) be a (p, q) graph. Define rho = {p/2 p is even p-1/2 pis odd, and M = {+/- 1, +/- 2, +/- rho} called the set of labels. Consider a mapping lambda : V -> M by assigning different labels in M to the different elements of V when p is even and different labels in M to p-1 elements of V and repeating a label for the remaining one vertex when p is odd. The labeling as defined above is said to be a pair mean cordial labeling if for each edge uv of G, there exists a labeling lambda(u)+lambda(v)/2 if lambda(u) +lambda(v) is even and lambda(u)+lambda(v)+1/2 2 if lambda(u)+lambda(v) is odd such that vertical bar(S) over bar (lambda 1) - (S) over bar (lambda c1)vertical bar < 1 where <(S)over bar>(lambda 1) and (S) over bar (lambda c1) respectively denote the number of edges labeled with 1 and the number of edges not labeled with 1. A graph G for which there exists a pair mean cordial labeling is called a pair mean cordial graph. In this paper, we examine the pair mean cordial labeling of some graphs including lily graph, torch graph, twig graph, triangular prism, parachute graph and diamond graph.