下证T可逆 由⑦有,U()T=E-U(4)(E-B)R(x) 即E=U(4)T+U()(E-B)R() U (aT+(e-av(ar(a) [(E-A)Q()+U]7+(aE-A)V()R(2) 7+(E-)o(x)+(4)3(2) 比较两端,得 (E-4()+()2R(x)=0下证T可逆. 由⑦有， U T E U E B R (    ) = − − ( )( ) ( ). 即 E U T U E B R = + − (    ) ( )( ) ( ) ( ) ( ) ( ) ( ) 1 U T E A V R     − = + − ( ) ( ) ( ) ( ) ( ) 1      E A Q U T E A V R 0 − = − + + −     ( ) ( ) ( ) ( ) 1 U T E A Q V R 0     − = + − +     比较两端，得 ( ) ( ) ( ) ( ) 1     E A Q V R 0 − − + =    