Timeline for Periodic point-free maps and free ultrafilters.
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 11, 2013 at 23:31 | comment | added | Santi Spadaro | Hi Joel, thanks for the cute proof and the extensive references! | |
| Mar 11, 2013 at 23:28 | vote | accept | Santi Spadaro | ||
| Mar 11, 2013 at 0:38 | comment | added | Joel David Hamkins | Although the question only states as its hypothesis the implication that $A\in\mu\to f^{-1}A\in\mu$, in fact this implies the biconditional $A\in\mu\leftrightarrow f^{-1}A\in\mu$, since if $A\notin\mu$, then $X-A\in\mu$ and so $f^{-1}(X-A)\in\mu$, which is disjoint from $f^{-1}A$. | |
| Mar 10, 2013 at 21:15 | history | answered | Joel David Hamkins | CC BY-SA 3.0 |