实Hilbert空间中点到无穷余维子空间的距离

On the Distance from a Point to a Subspace of Infinite Codimension in a Real Hilbert Space

设H是实Hilbert空间，M是可对个连续线性泛函零空间的交，本文得到了点到M或仿射子空间M＋u的最佳逼近元及距离公式。

In this paper,let H is a real Hilbert space,M is the. intersection of the null spaces of countable number ofcontinuous linear functionals on H,we obtain formulas for the element of lest anyfoyimation and the distancefrom a point to M (or M + u,an affine subspace).