(0, ½, 1) matrices which are extreme points of the generalized transitive tournament polytope Original Research Article

Following Brualdi and Hwang, given a generalized transitive tournament (GTT) matrix T of ordern, we consider the *-graph ofT, that is, the undirected graph with vertices 1, 2, …,n in which there is an edge {i,j} between verticesi andj if and only if0 < tij < 1. We characterize the *-graphs of the extreme GTT (0, ½, 1) matrices of order n. Using this characterization, we obtain for n = 6, 7 the complete list of extreme GTT (0, ½, 1) matrices of ordern.