Timeline for Indecomposable objects in a category
Current License: CC BY-SA 2.5
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 18, 2010 at 18:42 | comment | added | Finn Lawler | Thanks again, all. I've added some of this to nlab: ncatlab.org/nlab/show/indecomposable+object | |
| Aug 18, 2010 at 17:00 | history | edited | Peter LeFanu Lumsdaine | CC BY-SA 2.5 |
incorporated Mike S's corrections/additions
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| Aug 18, 2010 at 7:49 | comment | added | Andrej Bauer | I suppose computer jokes don't work on a math forum... | |
| Aug 18, 2010 at 4:50 | comment | added | Mike Shulman | Already in a pretopos all epis are regular; see A1.4.9 in the Elephant. However, even in a topos the Elephant definition does not imply the LS definition except for projective objects. For instance, if X is a connected space which is the (non-disjoint) union of two proper open subsets U and V, then in the topos Sh(X) the terminal object is not a nontrivial coproduct, but the map from U+V to the terminal object is epi although neither component is so. | |
| Aug 18, 2010 at 4:43 | comment | added | Mike Shulman | Andrej, your link takes me back to this page. | |
| Aug 17, 2010 at 23:17 | comment | added | Andrej Bauer | Here's a good reference for this sort of thing: tiny.cc/pvgq6 | |
| Aug 17, 2010 at 18:36 | comment | added | Peter LeFanu Lumsdaine | Thanks, glad to help! Sorry I can't suggest a reference though… | |
| Aug 17, 2010 at 18:34 | history | edited | Peter LeFanu Lumsdaine | CC BY-SA 2.5 |
filled in promised details
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| Aug 17, 2010 at 16:56 | comment | added | Finn Lawler | Thanks, this is exactly the sort of thing I was looking for. | |
| Aug 17, 2010 at 16:55 | vote | accept | Finn Lawler | ||
| Aug 17, 2010 at 16:19 | history | answered | Peter LeFanu Lumsdaine | CC BY-SA 2.5 |