On the Hull Number of the Composition of Graphs

Sergio R.Canoy,Jr.1, Gilbert B.Cagaanan 2
1Department of Mathematics CSM, MSU-lligan Institute of Technology 9200 Lligan City, Philippines
2Related Subjects Department SET, MSU-lIligan Institute of Technology 9200 Tligan City, Philippines

Abstract

The convex hull of a subset \(A\) of \(V(G)\), where \(G\) is a connected graph, is defined as the smallest convex set in \(G\) containing \(A\). The hull number of \(G\) is the cardinality of a smallest set \(A\) whose convex hull is \(V(G)\). In this paper, we give the hull number of the composition of two connected graphs.