On a conjecture about the kth lower multiexponent

AbstractIn this paper, the conjecture about the kth lower multiexponent f(n,k) proposed by R.A. Brualdi and B. Liu is proved to be true for the following cases: (1) k=n−i, where i=2,3,4,5; (2) small n, where n≤8; (3) the class of primitive micro-symmetric digraphs of order n