added pointer (here) to where Borceux & Bourn prove that Grp is protomodular.
]]>Added link to Bourn’s excellent 2017 introductory textbook on his research: From Groups to Categorial Algebra : Introduction to Protomodular and Mal’tsev Categories
]]>The page now links to normal monomorphism, but that specifies pointedness, when Bourn talks about normal morphisms in non-pointed protomodular categories.
]]>I added some content in protomodular category. It’s mostly drawn from Bourn’s papers. It will need brushing up, cross-linking, etc.
There are many further related concepts. Don’t know how important they are, e.g., Bourn says
The dual of a topos is arithmetical.
Is that a standard concept? And ’affine categories’?
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