Timeline for On the large cardinals foundations of categories
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
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| May 15, 2013 at 9:19 | comment | added | Zhen Lin | Yes, that definition is much closer to that of a Grothendieck universe. | |
| May 15, 2013 at 0:29 | comment | added | David Roberts♦ | Actually, I should say that a universe in a topos is an internal category which is a topos, and whose externalisation is a logical full subtopos of the codomain topos (as fibred toposes). So I imagine that the internal logic of the ambient topos, which is higher order, can give you this. I meant to link to the nlab page ncatlab.org/nlab/show/universe+in+a+topos, where this can probably be seen rather more easily. | |
| May 14, 2013 at 8:24 | comment | added | Zhen Lin | A universe in the sense of Grothendieck et al. satisfies a second-order replacement axiom. How do we guarantee this using the fibred topos language? | |
| May 14, 2013 at 7:50 | history | edited | David Roberts♦ | CC BY-SA 3.0 |
added 2 characters in body
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| May 14, 2013 at 7:43 | history | answered | David Roberts♦ | CC BY-SA 3.0 |