Timeline for The conceptual difference in notations of Cat
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 12, 2017 at 10:46 | comment | added | Peter Heinig | To add more context to Mike Shulman's comment: Johnstone practices the same in 'A Topos Theory Compendium' (see 'Index of Notation'): $\mathbf{Cat}$ is for the 1-category, and $\mathfrak{Cat}$ is for (Johnstone's version of) the relevant 2-category. | |
| Oct 6, 2017 at 16:45 | comment | added | Mike Shulman | Like many other notations in mathematics, the meaning of "Cat" is context-dependent. If I'm writing a paper in which I need to discuss both meanings, I sometimes use different fonts, e.g. $\mathbf{Cat}$ for the 1-category and $\mathcal{C}\mathit{at}$ for the 2-category. | |
| Oct 6, 2017 at 15:37 | answer | added | Colin McLarty | timeline score: 7 | |
| Oct 6, 2017 at 14:59 | comment | added | Denis Nardin | It's even worse: I usually use Cat to denote the (2,1)-category of small categories (so a third possible meaning)! I imagine this happens because people routinely use only one of the meanings, and so never find useful to mention the other two possibilities... | |
| Oct 6, 2017 at 14:55 | review | First posts | |||
| Oct 6, 2017 at 16:01 | |||||
| Oct 6, 2017 at 14:50 | history | asked | Frechet | CC BY-SA 3.0 |