Tall F_σ subideals of tall analytic ideals

2020/09/28 by Jan Grebík, Grebík, Jan, Zoltán Vidnyánszky +1
Mathematics · #Advanced Topology and Set Theory #Rings, Modules, and Algebras #Meromorphic and Entire Functions

paper · pdf · doi:10.48550/arxiv.2009.13686

Abstract

Answering a question of Hrušák, we show that every analytic tall ideal on ω contains an F_σ tall ideal. We also give an example of an F_σ tall ideal without a Borel selector.

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