English

A Dedekind Finite Borel Set

Logic 2008-06-13 v1

Abstract

In this paper we prove three theorems about the theory of Borel sets in models of ZF without any form of the axiom of choice. We prove that if B is a G-delta-sigma set, then either B is countable or B contains a perfect subset. Second, we prove that if the real line is the countable union of countable sets, then there exists an F-sigma-delta set which is uncountable but contains no perfect subset. Finally, we construct a model of ZF in which we have an infinite Dedekind finite set of reals which is F-sigma-delta.

Keywords

Cite

@article{arxiv.0806.1957,
  title  = {A Dedekind Finite Borel Set},
  author = {Arnold W. Miller},
  journal= {arXiv preprint arXiv:0806.1957},
  year   = {2008}
}

Comments

Latex2e: 21 pages Latest version at http://www.math.wisc.edu/~miller

R2 v1 2026-06-21T10:49:45.211Z