One Repeat Point Gives a Closed, Unbounded Ultrafilter on \ω₁

2014/03/19 by William J. Mitchell, Mitchell, William J.
Computer Science · Mathematics · #03E25 #03E35 #Advanced Topology and Set Theory #Computability, Logic, AI Algorithms #FOS: Mathematics #Logic (math.LO) #Mathematical and Theoretical Analysis

paper · pdf · doi:10.48550/arxiv.1403.4690

openalex publication_date 2014/03/19 · openalex created_date 2022/08/31 · openalex updated_date 2026/07/28

Abstract

It is shown that the consistency strength of ZF + DC + "the closed unbounded\nultrafilter on omega₁ is an ultrafilter" is exactly ZFC + one measurable\ncardinal.\n

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