Timeline for About the characterization of categories of model of algebraic theories
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
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| Apr 8 at 12:11 | comment | added | Arnaud D. | For what it's worth, in the next chapter, Borceux gives a similar description of categories monadic over sets (Theorem 4.4.5), which mentions a regular projective generator instead of a left adjoint, but also replaces condition 1 by the condition that $C$ is exact. He also explicitly gives torsion-free abelian groups as a counterexample (4.4.6). | |
| Apr 8 at 11:55 | vote | accept | Simon Henry | ||
| Apr 7 at 4:41 | history | became hot network question | |||
| Apr 7 at 1:31 | comment | added | Maxime Ramzi | This seems to be a(n at least somewhat) common mistake, there was a similar question a few years ago asking if 4 and 4' were equivalent iirc | |
| Apr 7 at 0:19 | comment | added | Todd Trimble | It seems that Borceux is probably basing himself on Linton, F.E.J. (1966). Some Aspects of Equational Categories. In: Eilenberg, S., Harrison, D.K., MacLane, S., Röhrl, H. (eds) Proceedings of the Conference on Categorical Algebra. Springer, Berlin, Heidelberg. doi.org/10.1007/978-3-642-99902-4_3, but with a slight difference in formulation. I'll try to track down what is going on here (although you might beat me to it). | |
| Apr 6 at 23:46 | answer | added | Todd Trimble | timeline score: 8 | |
| Apr 6 at 20:40 | history | asked | Simon Henry | CC BY-SA 4.0 |