Independence graph of a graph

Independence graph of a graph --- граф независимости графа.

Maximum independent sets in [math]\displaystyle{ G }[/math] will be also called [math]\displaystyle{ \alpha }[/math]--sets in [math]\displaystyle{ G }[/math]. The independence number [math]\displaystyle{ \alpha(G) }[/math] of a graph [math]\displaystyle{ G }[/math] is the cardinality of an [math]\displaystyle{ \alpha }[/math]--set in [math]\displaystyle{ G }[/math]. Let [math]\displaystyle{ {\mathcal S} }[/math] be the set of [math]\displaystyle{ \alpha }[/math]--sets of [math]\displaystyle{ G }[/math]. Then the independence graph [math]\displaystyle{ Ind(G) }[/math] of [math]\displaystyle{ G }[/math] is the graph with [math]\displaystyle{ V(Ind(G)) = {\mathcal S} }[/math], and [math]\displaystyle{ S_{1}, S_{2} \in {\mathcal S} }[/math] are adjacent whenever [math]\displaystyle{ S_{1} \cap S_{2} = \emptyset }[/math].