pith. sign in

arxiv: 0806.1957 · v1 · submitted 2008-06-11 · 🧮 math.LO

A Dedekind Finite Borel Set

classification 🧮 math.LO
keywords countableproveborelcontainsdedekindf-sigma-deltafiniteperfect
0
0 comments X
read the original 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.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.