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Making doughnuts of Cohen reals.

Authors :
Halbeisen, Lorenz
Source :
Mathematical Logic Quarterly. Mar2003, Vol. 49 Issue 2, p173-178. 6p.
Publication Year :
2003

Abstract

For a ⊆ b ⊆ ω with b\ a infinite, the set D = {x ∈ [ω]ω : a ⊆ x ⊆ b} is called a doughnut. A set S ⊆ [ω]ω has the doughnut property 𝒟 if it contains or is disjoint from a doughnut. It is known that not every set S ⊆ [ω]ω has the doughnut property, but S has the doughnut property if it has the Baire property ℬ or the Ramsey property ℛ. In this paper it is shown that a finite support iteration of length ω1 of Cohen forcing, starting from <BI>L</BI>, yields a model for CH + <UEQN>$ \sum ^1 _2 $</UEQN>(𝒟) + <UEQN>$ \neg \sum ^1 _2 $</UEQN>(ℬ) + <UEQN>$ \neg \sum ^1 _2 $</UEQN>(ℛ). [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
09425616
Volume :
49
Issue :
2
Database :
Academic Search Index
Journal :
Mathematical Logic Quarterly
Publication Type :
Academic Journal
Accession number :
13643760
Full Text :
https://doi.org/10.1002/malq.200310016