LOGO c11 c12 c 1 21 c22 −1 t det ( A ) ≠ 0, A = C = L det ( A ) det ( A ) L cn1 cn c11 c21 c12 c22 = L det ( A ) L c1n c2 n L L O L L L O L t c1n c2 n = L cnn cn1 cn L cnn