Mathematics Department, Technion-Israel Institute of Technology, Haifa 32000, Israel
IBM Israel-Science and Technology, Technion City, Haifa 32000, Israel
Abstract:
Linial conjectured that Greene—Kleitman's theorem can be extended to general digraphs. We prove a stronger conjecture of Berge for digraphs having k-optimal path partitions consisting of ‘long’ paths. The same method yields known results for acyclic digraphs, and extensions of various theorems of Greene and Frank to acyclic digraphs.