A Note On Set-Indexed Graphs

Abstract

A set-indexer [1] of the graph G is an assignment of distinct subsets of a finite set X to the vertices of the graph, where the sets on the edges are obtained as the symmetric differences of the sets assigned to their end vertices which are also distinct. A set-indexer is called a set-sequential if sets on the vertices and edges are distinct and together form the set of all nonempty subsets of X. A set-indexer is called a set-graceful if all the nonempty subsets of X are obtained on the edges. A graph is called set-sequential (set-graceful) if it admits a set-sequential (set-graceful) labeling. The objective of this note is to report some new results, open problems and conjectures in relation to set-indexed graphs.

Keywords:

• Set-indexed graphs
• Set-graceful graphs
• Set-sequential graphs

Mathematics Subject Classification (2010):

• 05C22