Timeline for Unnecessary uses of the axiom of choice
Current License: CC BY-SA 4.0
4 events
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| Feb 18, 2022 at 21:20 | history | edited | LSpice | CC BY-SA 4.0 |
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| Feb 18, 2022 at 17:00 | comment | added | Pedro Lauridsen Ribeiro | I've presented this in a graduate course without being aware of the math.SE answer you've linked. I had a faint memory this had been done in some textbook, but cannot recall which one (if it exists at all). What I did was essentially the same as in the math.SE answer (proving first that $C^r$-compatibility of $C^r$ atlases is an equivalence relation in order to show that the union of all $C^r$-compatible atlases is the maximal $C^r$-compatible atlas), but I only glossed over the set-theoretic subtleties regarding the set of all $n$-dimensional $C^r$ atlases on a given set. Thanks for the link! | |
| S Feb 18, 2022 at 11:59 | history | answered | Tom Leinster | CC BY-SA 4.0 | |
| S Feb 18, 2022 at 11:59 | history | made wiki | Post Made Community Wiki by Tom Leinster |