for (i=0 to k-2 by 1) =coeff1(i+1); =coeff2(i); ; endfor for (i=k-1 to n by 1) ; for (i=0 to -1 by 1) ; ;

;

    其中, coeff1() 和coeff2()为根据公式(6-4-11)或(6-4-13)计算系数 αi和 βi的函数。