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arXiv · 1403.4690

One Repeat Point Gives a Closed, Unbounded Ultrafilter on {\omega_1}

William J. Mitchell
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Abstract

It is shown that the consistency strength of ZF + DC + "the closed unbounded ultrafilter on omega_1 is an ultrafilter" is exactly ZFC + one measurable cardinal.

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William J. Mitchell. 2014-03-19. One Repeat Point Gives a Closed, Unbounded Ultrafilter on {\omega_1}. https://arxiv.org/abs/1403.4690

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