摘要
Let X<sub>n</sub>={x<sub>nk</sub>}<sub>k</sub><sup>n</sup>=1 be a set of real numbers satisfying -1【x<sub>nn</sub>【…【x<sub>n1</sub>【1, q’, q: 0≤q’≤q be two integers. For a non-negative integer r, we denote by C<sub>[</sub>-1,1]<sup>r</sup> the set of all the rth continuously differentiable real-valued functions on [-1, 1], and by ∏<sub>r</sub> the set of the polynomials of degree at most r. For a given f ∈C<sub>[</sub>-1,1]<sup>q’</sup>, we call the only S<sub>N</sub>（f, x）∈∏<sub>N</sub> （N = （q+1） n-1）
