isClique gr ns = null .
                 foldl1' intersect .
                 map ((\\ ns) . twoCycle gr) $ ns
isClique gr ns = null .
                 foldl1' intersect .
                 map ((\\ ns) . twoCycle gr) $ ns
isClique gr ns = null .
                 foldl1' intersect .
                 map ((\\ ns) . twoCycle gr) $ ns