Timeline for How to formally -- and cleanly -- express relationships of limits of diagrams?
Current License: CC BY-SA 2.5
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 20, 2010 at 14:04 | vote | accept | Thomas Belulovich | ||
| Apr 20, 2010 at 11:47 | comment | added | Thomas Belulovich | @angoleirovero Yes, I believe so. I wrote up the question very late last night and I was probably being too cautious. | |
| Apr 20, 2010 at 8:49 | answer | added | Martin Brandenburg | timeline score: 3 | |
| Apr 20, 2010 at 7:54 | comment | added | babubba | In what sense does your category have to be 'nice enough' for the identity between pullbacks to hold? Shouldn't it be true in any category where the necessary pullbacks exist? | |
| Apr 20, 2010 at 6:15 | comment | added | Steven Sam | For your example, one can use Yoneda's lemma to reduce proving the isomorphism to doing it in the category of sets "naturally". In this case, these fiber products are concrete things to deal with, such isomorphisms are easy to come by. We can use this technique for any category where the relevant fiber products exist. | |
| Apr 20, 2010 at 5:40 | history | asked | Thomas Belulovich | CC BY-SA 2.5 |