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Timeline for answer to Freyd-Mitchell for $k$-linear categories by user144185

Current License: CC BY-SA 4.0

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Apr 22, 2020 at 14:11 vote accept 57Jimmy
Apr 22, 2020 at 11:29 comment added user144185 @JeremyRickard thank you! I edited the answer and I think that now it is right.
Apr 22, 2020 at 11:27 history edited user144185 CC BY-SA 4.0
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Apr 22, 2020 at 9:27 comment added Jeremy Rickard I agree with the conclusion that $R$ can be taken to be a $k$-algebra, with the embedding $k$-linear. But this is not how the Freyd-Mitchell embedding is constructed. Firstly, your construction embeds $\mathcal{A}$ into $\mathcal{L}(\mathcal{A}^{\text{op}},\operatorname{Ab})$, not $\mathcal{L}(\mathcal{A},\operatorname{Ab})$. And also, it is not true in general that $\mathcal{L}(\mathcal{A},\operatorname{Ab})$ has a projective generator. But it does have an injective cogenerator, which is what is used to construct the Freyd-Mitchell embedding.
Apr 22, 2020 at 1:47 history edited user144185 CC BY-SA 4.0
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Apr 21, 2020 at 22:53 history edited LSpice CC BY-SA 4.0
Link to book; proofreading and TeX
Apr 21, 2020 at 22:38 history edited user144185 CC BY-SA 4.0
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Apr 21, 2020 at 22:19 history answered user144185 CC BY-SA 4.0