Documentation

Mathlib.CategoryTheory.Functor.KanExtension.Adjunction

The Kan extension functor #

Given a functor L : C ⥤ D, we define the left Kan extension functor L.lan : (C ⥤ H) ⥤ (D ⥤ H) which sends a functor F : C ⥤ H to its left Kan extension along L. This is defined if all F have such a left Kan extension. It is shown that L.lan is the left adjoint to the functor (D ⥤ H) ⥤ (C ⥤ H) given by the precomposition with L (see Functor.lanAdjunction).

Similarly, we define the right Kan extension functor L.ran : (C ⥤ H) ⥤ (D ⥤ H) which sends a functor F : C ⥤ H to its right Kan extension along L.

The left Kan extension functor (C ⥤ H) ⥤ (D ⥤ H) along a functor C ⥤ D.

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    The natural transformation F ⟶ L ⋙ (L.lan).obj G.

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      instance CategoryTheory.Functor.instIsLeftKanExtensionObjLanAppLanUnit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] (F : CategoryTheory.Functor C H) :
      (L.lan.obj F).IsLeftKanExtension (L.lanUnit.app F)
      noncomputable def CategoryTheory.Functor.isPointwiseLeftKanExtensionLeftKanExtensionUnit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] :
      (CategoryTheory.Functor.LeftExtension.mk (L.leftKanExtension F) (L.leftKanExtensionUnit F)).IsPointwiseLeftKanExtension

      If there exists a pointwise left Kan extension of F along L, then L.lan.obj G is a pointwise left Kan extension of F.

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        noncomputable def CategoryTheory.Functor.leftKanExtensionObjIsoColimit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [L.HasLeftKanExtension F] (X : D) :
        (L.leftKanExtension F).obj X CategoryTheory.Limits.colimit ((CategoryTheory.CostructuredArrow.proj L X).comp F)

        If a left Kan extension is pointwise, then evaluating it at an object is isomorphic to taking a colimit.

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        • L.leftKanExtensionObjIsoColimit F X = (L.isPointwiseLeftKanExtensionLeftKanExtensionUnit F X).isoColimit
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          @[simp]
          theorem CategoryTheory.Functor.ι_leftKanExtensionObjIsoColimit_inv {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [L.HasLeftKanExtension F] (X : D) (f : CategoryTheory.CostructuredArrow L X) :
          CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.colimit.ι ((CategoryTheory.CostructuredArrow.proj L X).comp F) f) (L.leftKanExtensionObjIsoColimit F X).inv = CategoryTheory.CategoryStruct.comp ((L.leftKanExtensionUnit F).app f.left) ((L.leftKanExtension F).map f.hom)
          @[simp]
          theorem CategoryTheory.Functor.ι_leftKanExtensionObjIsoColimit_inv_assoc {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [L.HasLeftKanExtension F] (X : D) (f : CategoryTheory.CostructuredArrow L X) {Z : H} (h : (L.leftKanExtension F).obj X Z) :
          CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.colimit.ι ((CategoryTheory.CostructuredArrow.proj L X).comp F) f) (CategoryTheory.CategoryStruct.comp (L.leftKanExtensionObjIsoColimit F X).inv h) = CategoryTheory.CategoryStruct.comp ((L.leftKanExtensionUnit F).app f.left) (CategoryTheory.CategoryStruct.comp ((L.leftKanExtension F).map f.hom) h)
          @[simp]
          theorem CategoryTheory.Functor.ι_leftKanExtensionObjIsoColimit_hom {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] (X : D) (f : CategoryTheory.CostructuredArrow L X) :
          CategoryTheory.CategoryStruct.comp ((L.leftKanExtensionUnit F).app f.left) (CategoryTheory.CategoryStruct.comp ((L.leftKanExtension F).map f.hom) (L.leftKanExtensionObjIsoColimit F X).hom) = CategoryTheory.Limits.colimit.ι ((CategoryTheory.CostructuredArrow.proj L X).comp F) f

          The left Kan extension of F : C ⥤ H along a functor L : C ⥤ D is isomorphic to the fiberwise colimit of the projection functor on the Grothendieck construction of the costructured arrow category composed with F.

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            theorem CategoryTheory.Functor.leftKanExtensionIsoFiberwiseColimit_inv_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [L.HasLeftKanExtension F] (X : D) :
            (L.leftKanExtensionIsoFiberwiseColimit F).inv.app X = CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.HasColimit.isoOfNatIso (CategoryTheory.isoWhiskerRight (CategoryTheory.CostructuredArrow.ιCompGrothendieckProj L X) F)).hom (L.leftKanExtensionObjIsoColimit F X).inv
            @[simp]
            theorem CategoryTheory.Functor.leftKanExtensionIsoFiberwiseColimit_hom_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [L.HasLeftKanExtension F] (X : D) :
            (L.leftKanExtensionIsoFiberwiseColimit F).hom.app X = CategoryTheory.CategoryStruct.comp (L.leftKanExtensionObjIsoColimit F X).hom (CategoryTheory.Limits.HasColimit.isoOfNatIso (CategoryTheory.isoWhiskerRight (CategoryTheory.CostructuredArrow.ιCompGrothendieckProj L X) F)).inv

            The left Kan extension functor L.Lan is left adjoint to the precomposition by L.

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              theorem CategoryTheory.Functor.lanAdjunction_unit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) (H : Type u_3) [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] :
              (L.lanAdjunction H).unit = L.lanUnit
              theorem CategoryTheory.Functor.lanAdjunction_counit_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] (G : CategoryTheory.Functor D H) :
              (L.lanAdjunction H).counit.app G = (L.lan.obj (L.comp G)).descOfIsLeftKanExtension (L.lanUnit.app (L.comp G)) G (CategoryTheory.CategoryStruct.id (L.comp G))
              @[simp]
              theorem CategoryTheory.Functor.lanUnit_app_app_lanAdjunction_counit_app_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] (G : CategoryTheory.Functor D H) (X : C) :
              CategoryTheory.CategoryStruct.comp ((L.lanUnit.app (L.comp G)).app X) (((L.lanAdjunction H).counit.app G).app (L.obj X)) = CategoryTheory.CategoryStruct.id (((CategoryTheory.Functor.id (CategoryTheory.Functor C H)).obj (L.comp G)).obj X)
              @[simp]
              theorem CategoryTheory.Functor.lanUnit_app_app_lanAdjunction_counit_app_app_assoc {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] (G : CategoryTheory.Functor D H) (X : C) {Z : H} (h : G.obj (L.obj X) Z) :
              CategoryTheory.CategoryStruct.comp ((L.lanUnit.app (L.comp G)).app X) (CategoryTheory.CategoryStruct.comp (((L.lanAdjunction H).counit.app G).app (L.obj X)) h) = h
              noncomputable def CategoryTheory.Functor.lanCompColimIso {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] [CategoryTheory.Limits.HasColimitsOfShape C H] [CategoryTheory.Limits.HasColimitsOfShape D H] :
              L.lan.comp CategoryTheory.Limits.colim CategoryTheory.Limits.colim

              Composing the left Kan extension of L : C ⥤ D with colim on shapes D is isomorphic to colim on shapes C.

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                @[simp]
                theorem CategoryTheory.Functor.lanCompColimIso_inv_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] [CategoryTheory.Limits.HasColimitsOfShape C H] [CategoryTheory.Limits.HasColimitsOfShape D H] (X : CategoryTheory.Functor C H) :
                L.lanCompColimIso.inv.app X = ((L.lan.obj X).colimitIsoOfIsLeftKanExtension (L.lanUnit.app X)).inv
                @[simp]
                theorem CategoryTheory.Functor.lanCompColimIso_hom_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] [CategoryTheory.Limits.HasColimitsOfShape C H] [CategoryTheory.Limits.HasColimitsOfShape D H] (X : CategoryTheory.Functor C H) :
                L.lanCompColimIso.hom.app X = ((L.lan.obj X).colimitIsoOfIsLeftKanExtension (L.lanUnit.app X)).hom

                If G : C ⥤ H admits a left Kan extension along a functor L : C ⥤ D and H has colimits of shape C and D, then the colimit of G is isomorphic to the colimit of a canonical functor Grothendieck (CostructuredArrow.functor L) ⥤ H induced by L and G.

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                  instance CategoryTheory.Functor.instIsIsoAppLanUnit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) (X : C) [L.HasPointwiseLeftKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] :
                  CategoryTheory.IsIso ((L.lanUnit.app F).app X)
                  instance CategoryTheory.Functor.instIsIsoAppLanUnit_1 {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] :
                  CategoryTheory.IsIso (L.lanUnit.app F)
                  instance CategoryTheory.Functor.coreflective {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] [∀ (F : CategoryTheory.Functor C H), L.HasPointwiseLeftKanExtension F] :
                  instance CategoryTheory.Functor.instIsIsoAppUnitLanAdjunctionOfHasPointwiseLeftKanExtension {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) [L.HasPointwiseLeftKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasLeftKanExtension F] :
                  CategoryTheory.IsIso ((L.lanAdjunction H).unit.app F)
                  instance CategoryTheory.Functor.coreflective' {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] [∀ (F : CategoryTheory.Functor C H), L.HasPointwiseLeftKanExtension F] :
                  CategoryTheory.IsIso (L.lanAdjunction H).unit

                  The right Kan extension functor (C ⥤ H) ⥤ (D ⥤ H) along a functor C ⥤ D.

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                    The natural transformation L ⋙ (L.lan).obj G ⟶ L.

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                      instance CategoryTheory.Functor.instIsRightKanExtensionObjRanAppRanCounit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) :
                      (L.ran.obj F).IsRightKanExtension (L.ranCounit.app F)
                      noncomputable def CategoryTheory.Functor.isPointwiseRightKanExtensionRanCounit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] :
                      (CategoryTheory.Functor.RightExtension.mk (L.ran.obj F) (L.ranCounit.app F)).IsPointwiseRightKanExtension

                      If there exists a pointwise right Kan extension of F along L, then L.ran.obj G is a pointwise right Kan extension of F.

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                        noncomputable def CategoryTheory.Functor.ranObjObjIsoLimit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] (X : D) :

                        If a right Kan extension is pointwise, then evaluating it at an object is isomorphic to taking a limit.

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                        • L.ranObjObjIsoLimit F X = (L.isPointwiseRightKanExtensionRanCounit F X).isoLimit
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                          @[simp]
                          theorem CategoryTheory.Functor.ranObjObjIsoLimit_hom_π {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] (X : D) (f : CategoryTheory.StructuredArrow X L) :
                          CategoryTheory.CategoryStruct.comp (L.ranObjObjIsoLimit F X).hom (CategoryTheory.Limits.limit.π ((CategoryTheory.StructuredArrow.proj X L).comp F) f) = CategoryTheory.CategoryStruct.comp ((L.ran.obj F).map f.hom) ((L.ranCounit.app F).app f.right)
                          @[simp]
                          theorem CategoryTheory.Functor.ranObjObjIsoLimit_hom_π_assoc {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] (X : D) (f : CategoryTheory.StructuredArrow X L) {Z : H} (h : F.obj ((CategoryTheory.StructuredArrow.proj X L).obj f) Z) :
                          @[simp]
                          theorem CategoryTheory.Functor.ranObjObjIsoLimit_inv_π {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] (X : D) (f : CategoryTheory.StructuredArrow X L) :
                          CategoryTheory.CategoryStruct.comp (L.ranObjObjIsoLimit F X).inv (CategoryTheory.CategoryStruct.comp ((L.ran.obj F).map f.hom) ((L.ranCounit.app F).app f.right)) = CategoryTheory.Limits.limit.π ((CategoryTheory.StructuredArrow.proj X L).comp F) f
                          @[simp]
                          theorem CategoryTheory.Functor.ranObjObjIsoLimit_inv_π_assoc {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] (X : D) (f : CategoryTheory.StructuredArrow X L) {Z : H} (h : F.obj f.right Z) :

                          The right Kan extension functor L.ran is right adjoint to the precomposition by L.

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                            theorem CategoryTheory.Functor.ranAdjunction_counit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) (H : Type u_3) [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] :
                            (L.ranAdjunction H).counit = L.ranCounit
                            theorem CategoryTheory.Functor.ranAdjunction_unit_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (G : CategoryTheory.Functor D H) :
                            (L.ranAdjunction H).unit.app G = (L.ran.obj (L.comp G)).liftOfIsRightKanExtension (L.ranCounit.app (L.comp G)) G (CategoryTheory.CategoryStruct.id (L.comp G))
                            @[simp]
                            theorem CategoryTheory.Functor.ranCounit_app_app_ranAdjunction_unit_app_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (G : CategoryTheory.Functor D H) (X : C) :
                            CategoryTheory.CategoryStruct.comp (((L.ranAdjunction H).unit.app G).app (L.obj X)) ((L.ranCounit.app (L.comp G)).app X) = CategoryTheory.CategoryStruct.id (((CategoryTheory.Functor.id (CategoryTheory.Functor D H)).obj G).obj (L.obj X))
                            @[simp]
                            theorem CategoryTheory.Functor.ranCounit_app_app_ranAdjunction_unit_app_app_assoc {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_6, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] (G : CategoryTheory.Functor D H) (X : C) {Z : H} (h : G.obj (L.obj X) Z) :
                            CategoryTheory.CategoryStruct.comp (((L.ranAdjunction H).unit.app G).app (L.obj X)) (CategoryTheory.CategoryStruct.comp ((L.ranCounit.app (L.comp G)).app X) h) = h
                            noncomputable def CategoryTheory.Functor.ranCompLimIso {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (L : CategoryTheory.Functor C D) [∀ (G : CategoryTheory.Functor C H), L.HasRightKanExtension G] [CategoryTheory.Limits.HasLimitsOfShape C H] [CategoryTheory.Limits.HasLimitsOfShape D H] :
                            L.ran.comp CategoryTheory.Limits.lim CategoryTheory.Limits.lim

                            Composing the right Kan extension of L : C ⥤ D with lim on shapes D is isomorphic to lim on shapes C.

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                              theorem CategoryTheory.Functor.ranCompLimIso_hom_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (L : CategoryTheory.Functor C D) [∀ (G : CategoryTheory.Functor C H), L.HasRightKanExtension G] [CategoryTheory.Limits.HasLimitsOfShape C H] [CategoryTheory.Limits.HasLimitsOfShape D H] (X : CategoryTheory.Functor C H) :
                              L.ranCompLimIso.hom.app X = ((L.ran.obj X).limitIsoOfIsRightKanExtension (L.ranCounit.app X)).hom
                              @[simp]
                              theorem CategoryTheory.Functor.ranCompLimIso_inv_app {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_5, u_2} D] {H : Type u_3} [CategoryTheory.Category.{u_6, u_3} H] (L : CategoryTheory.Functor C D) [∀ (G : CategoryTheory.Functor C H), L.HasRightKanExtension G] [CategoryTheory.Limits.HasLimitsOfShape C H] [CategoryTheory.Limits.HasLimitsOfShape D H] (X : CategoryTheory.Functor C H) :
                              L.ranCompLimIso.inv.app X = ((L.ran.obj X).limitIsoOfIsRightKanExtension (L.ranCounit.app X)).inv
                              instance CategoryTheory.Functor.instIsIsoAppRanCounit {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) (X : C) [L.HasPointwiseRightKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] :
                              CategoryTheory.IsIso ((L.ranCounit.app F).app X)
                              instance CategoryTheory.Functor.instIsIsoAppRanCounit_1 {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] :
                              CategoryTheory.IsIso (L.ranCounit.app F)
                              instance CategoryTheory.Functor.reflective {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] [∀ (F : CategoryTheory.Functor C H), L.HasPointwiseRightKanExtension F] :
                              instance CategoryTheory.Functor.instIsIsoAppCounitRanAdjunctionOfHasPointwiseRightKanExtension {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] (F : CategoryTheory.Functor C H) [L.HasPointwiseRightKanExtension F] [∀ (F : CategoryTheory.Functor C H), L.HasRightKanExtension F] :
                              CategoryTheory.IsIso ((L.ranAdjunction H).counit.app F)
                              instance CategoryTheory.Functor.reflective' {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_4, u_1} C] [CategoryTheory.Category.{u_6, u_2} D] (L : CategoryTheory.Functor C D) {H : Type u_3} [CategoryTheory.Category.{u_5, u_3} H] [L.Full] [L.Faithful] [∀ (F : CategoryTheory.Functor C H), L.HasPointwiseRightKanExtension F] :
                              CategoryTheory.IsIso (L.ranAdjunction H).counit