Timeline for Example of an unnatural isomorphism
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 27, 2018 at 4:28 | comment | added | David Roberts♦ | It looks like there isn't even a natural transformation $\phi\colon (-)\sqcup 1 \Rightarrow \mathrm{id}$, since it would imply that every function in the category of infinite sets should preserve the basepoints that every set $X$ gets from $1 \to X\sqcup 1 \xrightarrow{\phi_X} X$, and this is not true. | |
| Nov 26, 2018 at 23:43 | comment | added | Amir Sagiv | Why? Can you add details or proof? | |
| Nov 26, 2018 at 21:40 | review | Late answers | |||
| Nov 26, 2018 at 21:52 | |||||
| Nov 26, 2018 at 21:20 | review | First posts | |||
| Nov 26, 2018 at 23:43 | |||||
| S Nov 26, 2018 at 21:20 | history | answered | guest | CC BY-SA 4.0 | |
| S Nov 26, 2018 at 21:20 | history | made wiki | Post Made Community Wiki by guest |