I don't think that's true. See, for example, Finding Maximum Flows in Undirected Graphs Seems Easier than Bipartite Matching (Karger-Levine, 1997): http://cite

I don't think that's true. See, for example, Finding Maximum Flows in Undirected Graphs Seems Easier than Bipartite Matching (Karger-Levine, 1997): http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.52.3087 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.52.3...