The hierarchy of omega1-Borel sets

Arnold W. Miller

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arXiv · 1107.5022

The hierarchy of omega1-Borel sets

Arnold W. Miller

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Abstract

The family omega1-Borel sets is the smallest family of subsets of the real line which contains the family of open sets and is closed under complementation and omega1 unions. We show: Theorem 1. MA+notCH implies this hierarchy has length omega2. Theorem 2. In the Cohen real model it has length either omega1+1 or omega1+2.

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BibTeX RIS

Arnold W. Miller. 2011-07-25. The hierarchy of omega1-Borel sets. https://arxiv.org/abs/1107.5022

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