A Short Proof of Seymour's Characterization of the Matroids with the Max-Flow Min-Cut Property

摘要

Seymour proved that the set of odd circuits of a signed binary matroid (M, ∑) has the Max-Flow Min-Cut property if and only if it does not contain a minor isomorphic to (M(K_4), E(K_4)). We give a shorter proof of this result.