Berge's conjecture

Berge's conjecture --- гипотеза Бержа.

In 1960, C.Berge conjectured that a graph is perfect iff none of its induced subgraphs is a [math]\displaystyle{ C_{2k+1} }[/math] or the complement of such a cycle, [math]\displaystyle{ k \geq 2 }[/math].

This conjecture is well-known as the Strong Perfect Graph Conjecture and is still open.