## JindÅ™ich 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

PDF