若不论 项 所含的符号,有:a11a23a32a44a55、a11a23a32a45a54、a11a23a34a42a55、
a11a23a34a45a52、a11a23a35a42a54、a11a23a35a44a52 六项;
若考虑符号,则 a11a23a32a44a55 的逆序为 1
a11a23a34a45a52 的逆序为 3
a11a23a35a42a54 的逆序为 3 ,则这三项取负号,其余取正号,
∴所求项为:-a11a23a32a44a55、+a11a23a32a45a54、+a11a23a34a42a55、-a11a23a34a45a52、
-a11a23a35a42a54、+a11a23a35a44a52 .