Assume that q(r) is a real-valued, compactly supported potential, q(r)=0 for \documentclass[12pt]{minimal}
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\begin{document}\end{document}, \documentclass[12pt]{minimal}
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\begin{document}\end{document}. Let \documentclass[12pt]{minimal}
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\begin{document}\end{document} be an arbitrary fixed subset of non-negative integers such that \documentclass[12pt]{minimal}
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\begin{document}\end{document}, and \documentclass[12pt]{minimal}
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\begin{document}\end{document} be fixed-energy phase shifts corresponding to q(r). The main result is: