[Merged by Bors] - feat: pushouts of monoids#8061
[Merged by Bors] - feat: pushouts of monoids#8061ChrisHughes24 wants to merge 150 commits intomasterfrom
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ChrisHughes24
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Oct 31, 2023
riccardobrasca
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Can you add the universal property in some form? It is essentially already there with lift and hom_ext_nonempty, but it would be nice to have bijection from maps from the pushout and maps such that...
Mathlib/GroupTheory/PushoutI.lean
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| - `Monoid.PushoutI.of`: the map from each Monoid in the family to the pushout | ||
| - `Monoid.PushoutI.lift`: the universal property used to define homomorphisms out of the pushout. | ||
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| - `Monoid.PushoutI.NormalWord`: a normal form for words in the pushout |
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This is in the second part.
I added it, but I never end up using these things. The full universal property is given by |
I agree that in practice one uses the explicit results, but I think it's nice to have it, since it really packages the universal property. Can you just add a TODO that says we want to add bors d+ |
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We already know that both Monoids and Groups have all colimits |
Co-authored-by: Chris Hughes <33847686+ChrisHughes24@users.noreply.github.com>
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Co-authored-by: Chris Hughes <33847686+ChrisHughes24@users.noreply.github.com>