A proof of Fulkerson's characterization of permutation matrices

@article{Cruse1975APO,
title={A proof of Fulkerson's characterization of permutation matrices},
author={A. B. Cruse},
journal={Linear Algebra and its Applications},
year={1975},
volume={12},
pages={21-28}
}

Abstract A method is described for obtaining the facets of certain convex polyhedra from the optimal solutions to a related linear programming problem. This approach provides a direct proof, via the duality principle, for a result of D.R. Fulkerson, and leads to a class of readily constructible examples of the so-called “blocking pairs” of polyhedra introduced by Fulkerson in [6].