Item 4.1.12.d.
Give an example of a graph \(G = (V,E)\) for which \(N(v) = \emptyset\) for some \(v \in V\text{.}\) Is there an example of such a graph for which \(N[u] = V\) for some other \(u \in V\) as well? Explain.
Give an example of a graph \(G = (V,E)\) for which \(N(v) = \emptyset\) for some \(v \in V\text{.}\) Is there an example of such a graph for which \(N[u] = V\) for some other \(u \in V\) as well? Explain.