Kozen, Dexter2009-06-252009-06-252009-06-25https://hdl.handle.net/1813/13018The lexicographic flow problem is a flow problem in which the edges are assigned priorities, and we wish to find a flow that is lexicographically maximum with respect to the priority assignment. The problem is reducible to a weighted flow problem, but we show that exponentially large weights are necessary in general. We then give an efficient direct algorithm that does not use weights.en-USflowtechnical report