Timeline for Is it consistent to have a function that is sensitive to subset relation from the power set of a set to that set?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 27, 2020 at 14:41 | comment | added | Andrés E. Caicedo | @Andreas Yes, this is in essence the argument. | |
| Jun 27, 2020 at 14:41 | vote | accept | Zuhair Al-Johar | ||
| Jun 27, 2020 at 14:36 | comment | added | Andreas Blass | An alternative proof of the result about $F:\mathcal W(S)\to S$ without introducing $\sigma\mathcal M$: If there were such an $F$, then define, by recursion on ordinals $\alpha$, $G(\alpha)=F(\{G(\beta):\beta<\alpha\})$ and note that $G$ maps all the ordinals one-to-one into $S$. (To avoid mentioning the proper class of all ordinals, just restrict to $\alpha<$ Hartogs number of $S$.) | |
| Jun 27, 2020 at 14:14 | history | answered | Andrés E. Caicedo | CC BY-SA 4.0 |