Let■be a Banach space.In this paper the sufficient and necessary condi-tions for an elementary operator on ■to be of f......

对n为偶数和奇数时分别给出了πn(x)=(1-x^2)P'n-1(x)零点上一类正则和一类奇异的（0,1…,m-2,m）插值，其中Pn-1表示n-1次Legendre......