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A counterexample to a result concerning controlled approximation. (English) Zbl 0592.41029
Summary: A result of Strang and Fix states that if the order of controlled approximation from a collection of locally supported elements is k, then there is a linear combination \(\Omega\) of those elements and their translates such that any polynomial of degree less than k can be reproduced by \(\Omega\) and its translates. This paper gives a counterexample to their result.

MSC:
41A29 Approximation with constraints
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