[Merged by Bors] - feat(Topology/Category): category of finite topological spaces#13485
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[Merged by Bors] - feat(Topology/Category): category of finite topological spaces#13485
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dagurtomas
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Jun 4, 2024
erdOne
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Jun 5, 2024
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| instance (X : FinTopCat) : TopologicalSpace ((forget FinTopCat).obj X) := | ||
| inferInstanceAs <| TopologicalSpace X | ||
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| instance (X : FinTopCat) : Fintype ((forget FinTopCat).obj X) := | ||
| X.fintype |
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Should the spelling be (forget _).obj X or X (from the CoeSort instance)?
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If this does not break things, I would favour the CoeSort versoin.
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The CoeSort version already works:
example (X : FinTopCat) : Fintype X := inferInstance
but
example (X : FinTopCat) : Fintype ((forget FinTopCat).obj X) := inferInstance
does not without the instance above and I think I'll need this one.
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It's sad that we need that. I really hope we can sort out the coercions of concrete categories one day.
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Should I do anything about this in this case or can we merge this PR then?
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Thanks! |
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🚀 Pull request has been placed on the maintainer queue by erdOne. |
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The category of finite topological spaces.
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Thanks for the reviews! |
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Pull request successfully merged into master. Build succeeded: |
AntoineChambert-Loir
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The category of finite topological spaces.
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The category of finite topological spaces.
This is needed to obtain the category of finite continuous
G-types for a topological groupG. This would then beContAction FinTopCat G.