3.
The chief purpose of this paper is to study the problem of existence of continuous selections for the metric projection and of convergence of best L
p–approximations in subspaces of polynomial spline functions defined on a real compact interval I. Nürnberger-Sommer [8] have shown that there exists a continuous selection s if and only if the numberof knots k is less than or equal to the order m of the splines. Using their construction of s the author [12] has proved that the sequence of best L
p–approximations of f converges to s(f) as ρ→∞ for every continuous function f. The main results of this paper say that also in the case when k>m there exists always a continuous selection s (it is even pointwise-Lipschitz-continuous and quasi-linear) provided that the approximation problem is restricted to certain subsets I
epsilon; of I. In addition it is shown that anologously as for k≤m the sequence of best L
papproximations of f converges to s(f) for every continuous function f on Iε
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