Timeline for Surjectivity from union of a set system to the set system
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Mar 18, 2015 at 18:35 | history | edited | Dominic van der Zypen | CC BY-SA 3.0 |
deleted 9 characters in body
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| Mar 18, 2015 at 15:05 | comment | added | Ramiro de la Vega | Noah is right. You should erase the ",$n\geq2$" to make it work. | |
| Mar 18, 2015 at 6:59 | comment | added | Noah Schweber | I don't think this works - as I wrote in my comment, I don't think there's an injection $f$ from $\bigcup\mathcal{A}$ to $\mathcal{A}$ satisfying $a\in f(a)$, since 0 and 1 must both be sent to the same place. | |
| Mar 18, 2015 at 6:50 | vote | accept | CommunityBot | ||
| Sep 2, 2015 at 16:36 | |||||
| Mar 18, 2015 at 6:42 | comment | added | Noah Schweber | If you mean $\{\{0, 1\}\}\cup . . .$, I don't think this works - what is the $f$? Otherwise - if we treat numbers as ordinals - 0 can't be in $\mathcal{A}$ since $\mathcal{A}$ should consist of nonempty sets only. | |
| Mar 18, 2015 at 6:41 | history | answered | Dominic van der Zypen | CC BY-SA 3.0 |