### On co-bicliques

A co-biclique of a simple undirected graph is the edge-set of two disjoint complete subgraphs of . (A co-biclique is the complement of a biclique.) A subset is an independent of if there is a co-biclique such that , otherwise is a dependent of . This paper describes the minimal dependents of . (A minimal dependent is a dependent such that any proper subset of is an independent.) It is showed that a minimum-cost dependent set of can be determined in polynomial time for any nonnegative cost...