“…Proof. Let (6) be a factorization of the matrix A corresponding to the factorization (4) of its canonical diagonal form O A, Then, when condition (5) holds, it follows from Theorem 2 of [5] that for the matrices A and B there exist matrices U, Vl, and V2, invertible over R, such that UAVI = D a and UBVz = D 8. Therefore we can write UAVI = UBV2V('ICVI and D A = DB~, where qJ = V~-ICVI.…”