Full friendly index set — I.

Abstract: Let be a graph, a vertex labeling induces an edge labeling defined by for each . For each, define and . We call friendly if . The full friendly index set of is the set of all possible values of , where is friendly. In this paper, we study the full friendly index sets of some standard graphs such as the complete graph , the cycle , fans and and the Cartesian product of and i.e. . [Copyright &y& Elsevier]