Strong dominating set

Strong dominating set --- строго доминирующее множество.

A subset [math]\displaystyle{ D }[/math] of [math]\displaystyle{ G }[/math] is a strong (weak) dominating set of [math]\displaystyle{ G }[/math], if for any vertex [math]\displaystyle{ y \in V(G) - D }[/math] there exists a vertex [math]\displaystyle{ x \in D }[/math] adjacent to [math]\displaystyle{ y }[/math] in [math]\displaystyle{ G }[/math] and such that [math]\displaystyle{ deg_{G}(x) \geq deg_{G}(y) }[/math] ([math]\displaystyle{ deg_{G}(x) \leq deg_{G}(y) }[/math]), respectively.