For a set S ⊆ V (G), if every vertex has a neighbor in S or has at least two vertices in S at distance two from it, then the set S is a disjunctive total dominating set of G. The minimum cardinality of such a set is equal ...

The well-known concept of domination in graphs is a good tool for analyzing situations that can be modeled by networks. Although a vertex in the graph can exert influence on, or dominate, all vertices in its immediate ...