Jindřich Zapletal
On the existence of a $\sigma $-closed dense subset

Comment.Math.Univ.Carolin. 51,3 (2010) 513-517.

Abstract:It is consistent with the axioms of set theory that there are two co-dense partial orders, one of them $\sigma $-closed and the other one without a $\sigma $-closed dense subset.

Keywords: forcing, sigma-closed dense subset
AMS Subject Classification: 03E40

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