Let γ(G), i(G), γS(G) and iS(G) denote the domination number, the independent domination number, the strong domination number and the independent strong domination number of a graph G, respectively. A graph G is called γi-perfect (domination perfect) if γ(H) = i(H), for every induced subgraph H of G. The classes of γγS-perfect, γSiS-perfect, iiS-perfect and γiS-perfect graphs are defined analog...

In [16] Nowakowski and Rall listed a series of conjectures involving several different graph products. particular, they conjectured that $$i(G\times H) \ge i(G)i(H)$$ where i(G) is the independent domination number G $$G\times H$$ direct product graphs H. We show this conjecture false, and, in fact, construct pairs for which $$\min \{i(G), i(H)\} - i(G\times H)$$ arbitrarily large. also give ex...