Provable Pi-1-2 Singletons

Sy D. Friedman

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Provable Pi-1-2 Singletons

Sy D. Friedman

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Abstract

In this note I show that a pi-1-2 singleton R of L-degree strictly between 0 and 0# can be obtained so as to be the unique solution to a pi-1-2 formula which provably has at most one solution, in the theory ZFC+(*) where (*) has the approximate strength of an ineffable cardinal.

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BibTeX RIS

Sy D. Friedman. 1993-02-04. Provable Pi-1-2 Singletons. https://arxiv.org/abs/math/9302201

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