Some New Results on Strong Integer Additive Set-Indexers of Graphs

Let $\mathbb{N}_0$ be the set of all non-negative integers. An integer additive set-indexer of a graph $G$ is an injective function $f:V(G)\to 2^{\mathbb{N}_0}$ such that the induced function $g_f:E(G) \rightarrow 2^{\mathbb{N}_0}$ defined by $f^+(uv) = f(u)+ f(v)$ is also injective. An IASI is said to be {\em $k$-uniform} if $|f^+(e)| = k$ for all $e\in E(G)$. In this paper, we introduce the notions of strong integer additive set-indexers and initiate a study of the graphs which admit strong integer additive set-indexers.