A note on sign-solvability of linear system of equations

Given an n×(n+I) sign matrix (Ab). we are concerned with the condition that guarantees the solution to Ax=b be of a fixded sign pattern. It is shown that each factor of det (1) corresponds. in aone to one way to DM-component of the bipartite graph representation of A. This fact is used to supplement the proof of the graph-theoretic characterization of sign-solvability obtained by Bassett et al. [1] and subsequent authors.