ai+ka; a+ka E(Uj(KD)A 另两种情形同理可证 1717 另两种情形同理可证 E (ij ( k)) A =    mj k i           1 1 1 1 1   + = mj i k j      1 1 i j i r kr jm A     +           = ⎯⎯⎯→             1 i j jmk         +  