旦 人」 学 十 十 22 2 2 十 2   + = + = . , 2 1 1 2 2 2 2 1 1 1 1 2 2 1 a x a x b a x a x b , 2 1 2 2 1 1 1 2 a a a a A =    + = + = . , 2 1 1 2 2 2 2 1 1 1 1 2 2 1 a x a x b a x a x b , 2 2 2 1 1 2 1 b a b a A =