... = V .) The domination number of G, denoted by γ(G), is the minimum cardinality of a dominatingset. A dominating set of G of cardinality γ(G) is called a γ(G)-set.If G does not contain a graph ... contain a triangle that contains two vertices of degree 2 in the resulting graph. Continuing this process, we would reach a contradictionsince the 4-cycle, which is the only graph in F4, contains ... G8with domination number 3We will use the following observation in the proof of Theorem 4.Observation 2 If G′is obtained from a graph G by attaching a G8-unit to a vertex v,then there exists...