Abstract
We show that there is a forcing extension in which any two ultrafilters on ω are nearly coherent and there is a non-meagre filter that is not nearly ultra. This answers Blass' longstanding question (1989) of whether the principle of near coherence of filters is strictly weaker than the filter dichotomy principle.
Original language | English |
---|---|
Pages (from-to) | 2305-2317 |
Number of pages | 13 |
Journal | Transactions of the American Mathematical Society |
Volume | 361 |
Issue number | 5 |
DOIs | |
State | Published - May 2009 |