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Hello, I don't know if this should be in algebraic topology instead of this, but I recently read https://erischel.com/the-homotopy-theory-of-groups/, and although it's supposed to be a pedagogical joke, I'm wondering if their approach could be generalized to model categories of any Generalized Algebraic Theory/Lawvere theory/insert your favorite way of talking about generators and relations. Does anyone have any thoughts about this?
Well I don't know if you noticed but in this model structure any map is both a cofibration and a fibration, and weak equivalences are the isomorphisms (that's the joke behind remark 2.4). This model structure exists on any category...
I don't think that's right, otherwise the situation in Example 4.1 could not happen. The real point is that Grp is not the category of groups.
Ah I hadn't noticed that Gpd wasn't the usual category of groups, so for me Example 4.1 was just plain false.