Timeline for Unnecessary uses of the axiom of choice
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 19, 2022 at 22:12 | comment | added | Elliot Glazer | The bijection is definable. I've posted an answer to the linked question. | |
| Feb 18, 2022 at 21:42 | comment | added | Elliot Glazer | This is provable in $Z,$ even in second-order arithmetic. The principle $ATR_0$ is equivalent to every uncountable closed set in a Polish space containing a perfect subset. | |
| S Feb 18, 2022 at 15:29 | history | answered | user21820 | CC BY-SA 4.0 | |
| S Feb 18, 2022 at 15:29 | history | made wiki | Post Made Community Wiki by user21820 |