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Theorems · Definition · category theory

CategoryTheory.Functor.sections

{J : Type u} →
  [inst : CategoryTheory.Category.{v, u} J] → (F : CategoryTheory.Functor J (Type w)) → Set ((j : J) → F.obj j)

The sections of a functor F : J ⥤ Type are the choices of a point u j : F.obj j for each j, such that F.map f (u j) = u j' for every morphism f : j ⟶ j'. We later use these to define limits in Type and in many concrete categories.

Defined in
Mathlib.CategoryTheory.Types.Basic
Cited by
140 results in Mathlib
Foundations
Depth 13 from the axioms, rests on 78 definitions · uses propext, Quot.sound
Assumes
CategoryTheory.Category

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

CategoryTheory.PreGaloisCategory.AutGalois · cited by 12PreGaloisCategory.AutGalo…SheafOfModules.Presentation.relations · cited by 10Presentation.relationsCategoryTheory.Functor.sectionsFunctor · cited by 8Functor.sectionsFunctorCategoryTheory.Limits.Types.sectionOfCone · cited by 8Types.sectionOfConePresheafOfModules.sections · cited by 7PresheafOfModules.sectionsCategoryTheory.Functor.WellOrderInductionData.lift · cited by 7WellOrderInductionData.li…Finset.all_card_le_biUnion_card_iff_exists_injective · cited by 6Finset.all_card_le_biUnio…CategoryTheory.Limits.Types.Small.limitCone · cited by 6Small.limitConeAlgebraicGeometry.Scheme.coprodPresheafObjIso · cited by 5Scheme.coprodPresheafObjI…CategoryTheory.Functor.sectionsEquivHom · cited by 5Functor.sectionsEquivHomCategoryTheory.Limits.Types.coneOfSection · cited by 5Types.coneOfSectionCategoryTheory.Limits.Types.isLimitEquivSections · cited by 5Types.isLimitEquivSectionsCategoryTheory.Limits.Types.limitCone · cited by 5Types.limitConeCategoryTheory.Presheaf.coconeCompShrinkYonedaHomEquiv · cited by 5Presheaf.coconeCompShrink…AlgebraicGeometry.tildeEquiv · cited by 4AlgebraicGeometry.tildeEq…DFunLike.coe · cited by 62936DFunLike.coeSet · cited by 53352SetCategoryTheory.Category · cited by 32673CategoryTheory.CategoryQuiver.Hom · cited by 32603Quiver.HomCategoryTheory.Functor.obj · cited by 19642Functor.objCategoryTheory.Functor · cited by 16252CategoryTheory.FunctorCategoryTheory.Functor.map · cited by 8698Functor.mapSet.ofPred · cited by 6101Set.ofPredCategoryTheory.ConcreteCategory.hom · cited by 4022ConcreteCategory.homFunctor.sectionsCITED BYCITES

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Cited by267

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