The cototal domination number of a graph

Abstract

A dominating set D of a graph G = (V, E) is a cototal dominating (c.t.d.) set if every vertex v ? V?D is not an isolated vertex in the induced subgraph V ? D>. The cototal domination number?cl (G) of G is the minimum cardinality of a c.t.d. set. The cototal domatic number dCt (G) of G is defined like domatic number d(G). In this paper, we establish some results concerning these parameters. © 1999 Taylor & Francis Group, LLC.