M12=b,M21=c,M22=aA11=d,A12=−b,A21=−c,A22=aM12=b,M21=c,M22=aA11=c,A12=−c,A21=−c,A22=aM12=b,M21=c,M22=aA11=d,A12=−c,A21=−b,A22=aM12=a,M21=c,M22=bA11=d,A12=−b,A21=−c,A22=a