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[Merged by Bors] - feat(Condensed): discrete-underlying adjunction #8270

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We define a functor, associating to an object of a concrete category with nice properties, a "discrete" condensed object, and prove that this functor is left adjoint to the forgetful functor from Condensed C to C.


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@dagurtomas dagurtomas added awaiting-review The author would like community review of the PR awaiting-CI t-category-theory Category theory labels Nov 8, 2023
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@joelriou joelriou added awaiting-author A reviewer has asked the author a question or requested changes and removed awaiting-review The author would like community review of the PR labels Nov 9, 2023
@dagurtomas dagurtomas added awaiting-review The author would like community review of the PR awaiting-CI and removed awaiting-author A reviewer has asked the author a question or requested changes labels Nov 9, 2023
Comment on lines 25 to 28
variable (D : Type w) [Category.{max v u} D]

/-- The constant presheaf functor is left adjoint to evaluation at a terminal object. -/
noncomputable def constantPresheafAdj {T : C} (hT : IsTerminal T) :
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variable (D : Type w) [Category.{max v u} D]
/-- The constant presheaf functor is left adjoint to evaluation at a terminal object. -/
noncomputable def constantPresheafAdj {T : C} (hT : IsTerminal T) :
variable (D : Type w) [Category.{max v u} D]
/-- The constant presheaf functor is left adjoint to evaluation at a terminal object. -/
noncomputable def constantPresheafAdj {T : C} (hT : IsTerminal T) :

For this definition, the universe assumption on D could be relaxed.

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I just removed the explicit universes, Lean figures them out in the correct generality

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Thanks!

bors merge

@github-actions github-actions bot added ready-to-merge This PR has been sent to bors. and removed awaiting-review The author would like community review of the PR labels Nov 10, 2023
mathlib-bors bot pushed a commit that referenced this pull request Nov 10, 2023
We define a functor, associating to an object of a concrete category with nice properties, a "discrete" condensed object, and prove that this functor is left adjoint to the forgetful functor from `Condensed C` to `C`.
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mathlib-bors bot commented Nov 10, 2023

Pull request successfully merged into master.

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@mathlib-bors mathlib-bors bot changed the title feat(Condensed): discrete-underlying adjunction [Merged by Bors] - feat(Condensed): discrete-underlying adjunction Nov 10, 2023
@mathlib-bors mathlib-bors bot closed this Nov 10, 2023
@mathlib-bors mathlib-bors bot deleted the dagur_DiscreteCondensedAdjunction branch November 10, 2023 10:42
grunweg pushed a commit that referenced this pull request Dec 15, 2023
We define a functor, associating to an object of a concrete category with nice properties, a "discrete" condensed object, and prove that this functor is left adjoint to the forgetful functor from `Condensed C` to `C`.
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