A sufficient condition for a matrix to be totally unimodular
F. G. Commoner · Networks · 1973
Abstract Two conditions for a matrix to be totally unimodular are obtained; one sufficient, one necessary and sufficient. Both conditions involve a directed bipartite graph obtained from a {1, −1, 0}‐valued matrix, and both are generalizations of the fact that directed graphs and 2‐colorable undirected graphs have totally unimodular incidence matrices.