Timeline for MacLane coherence theorem for "monoidal" category without 1
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 7, 2018 at 9:57 | vote | accept | Atsche | ||
| Mar 7, 2018 at 0:49 | comment | added | Kevin Carlson | @მამუკა ჯიბლაძე Haha, you got me-similarly, I've heard of the rng of even integers. Atsche, that's a nice point. I think the ratio of people who mention Maclane's then to people who have actually read his paper is probably unjustly small. | |
| Mar 6, 2018 at 23:29 | comment | added | მამუკა ჯიბლაძე | @KevinCarlson finite abelian groups, say? | |
| Mar 6, 2018 at 21:37 | comment | added | Atsche | Well, but "pedagogically" it's not so wise in my opinion with regards to the pentagon axiom. I find it much better, as in MacLane's paper, to first introduce multiplication, then talk about what coherence means, then prove that coherence is equivalent to pentagon axiom, then introduce what a unit is. Suddenly, all makes sense. | |
| Mar 6, 2018 at 21:12 | comment | added | Kevin Carlson | I assume for similar reasons to the lack of emphasis on rings without unit in more classical algebra. I've never once encountered a monoidal category without unit in nature. | |
| Mar 6, 2018 at 20:53 | history | answered | Atsche | CC BY-SA 3.0 |