We have the following indirect implication of form equivalence classes:
| Implication | Reference |
|---|---|
| 384 \(\Rightarrow\) 14 |
"Maximal filters, continuity and choice principles", Herrlich, H. 1997, Quaestiones Math. |
| 14 \(\Rightarrow\) 385 | clear |
| 385 \(\Rightarrow\) 386 |
Products, the Baire category theorem, and the axiom of dependent choice, Herrlich-Keremedis-1999a[1999a], Topology and its Applications. |
Here are the links and statements of the form equivalence classes referenced above:
| Howard-Rubin Number | Statement |
|---|---|
| 384: | Closed Filter Extendability for \(T_1\) Spaces: Every closed filter in a \(T_1\) topological space can be extended to a maximal closed filter. |
| 14: | BPI: Every Boolean algebra has a prime ideal. |
| 385: | Countable Ultrafilter Theorem: Every proper filter with a countable base over a set \(S\) (in \({\cal P}(S)\)) can be extended to an ultrafilter. |
| 386: | Every B compact (pseudo)metric space is Baire. |
Comment: