因此 12 In n n nn 11 11 11 2 22 22 22 n-1,n nn n-1,n-1 ≌DU1÷÷÷÷÷÷øö ççççççèæ = nnnnn u u u u u u u u u u U ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 33 3 22 23 2 11 12 13 1 O M LLL ÷÷÷÷÷÷øö ççççççèæ = unn u u u ~ ~ ~ ~ 33 22 11 O ÷÷÷÷÷÷÷÷÷÷øö ççççççççççèæ× - - -1 ~~ 1 ~~ ~~ 1 ~~ ~~ ~~ 1 1, 1 1, 222 22 23 111 11 13 11 12 n n n n nn uuuu uu uu uu uu O LLL =ˆDU1 因此