W.Wang.J.Zhao Linear Algebra and its Applications 291 (1999)185-199 193 which is equivalent to 〔台任)g (18) Hence we have 创 (19) where e=diag(O,1). Since w=R-s1,moreover let V=-R-TY.Consequently,from Lemma 3.2. there exist M-invariant matrix O,such that ()-(8) ndg'(。)-(T further let (a)-() hence w=R-151. Note that w=R-s and hence from the definition of r,we have the relation ()-(）()） -(）eoa)-()） (20) Then we get