| In this paper it is shown that if C is an n×n complex matrix and C(k) is the k-th compound of C, 1≤k≤n, N = (n k) and if the eigenvalues of C(k) are labeled inorder of decreasing magnitude |λ1(C(k))|≥λ2(C(k))|≥…≥λN(C(k))|define the partial trace tri(k)(C) by (?) Then for two n×n Hermrtian matrices A, B,with equality holds if A, B are commutative or k = n. |
