Adjunctions and limits #
A left adjoint preserves colimits (CategoryTheory.Adjunction.leftAdjointPreservesColimits
),
and a right adjoint preserves limits (CategoryTheory.Adjunction.rightAdjointPreservesLimits
).
Equivalences create and reflect (co)limits.
(CategoryTheory.Adjunction.isEquivalenceCreatesLimits
,
CategoryTheory.Adjunction.isEquivalenceCreatesColimits
,
CategoryTheory.Adjunction.isEquivalenceReflectsLimits
,
CategoryTheory.Adjunction.isEquivalenceReflectsColimits
,)
In CategoryTheory.Adjunction.coconesIso
we show that
when F ⊣ G
,
the functor associating to each Y
the cocones over K ⋙ F
with cone point Y
is naturally isomorphic to
the functor associating to each Y
the cocones over K
with cone point G.obj Y
.
The right adjoint of Cocones.functoriality K F : Cocone K ⥤ Cocone (K ⋙ F)
.
Auxiliary definition for functorialityIsLeftAdjoint
.
Equations
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Instances For
The unit for the adjunction for Cocones.functoriality K F : Cocone K ⥤ Cocone (K ⋙ F)
.
Auxiliary definition for functorialityIsLeftAdjoint
.
Equations
- CategoryTheory.Adjunction.functorialityUnit adj K = CategoryTheory.NatTrans.mk fun (c : CategoryTheory.Limits.Cocone K) => CategoryTheory.Limits.CoconeMorphism.mk (adj.unit.app c.pt)
Instances For
The counit for the adjunction for Cocones.functoriality K F : Cocone K ⥤ Cocone (K ⋙ F)
.
Auxiliary definition for functorialityIsLeftAdjoint
.
Equations
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Instances For
The functor Cocones.functoriality K F : Cocone K ⥤ Cocone (K ⋙ F)
is a left adjoint.
Equations
- One or more equations did not get rendered due to their size.
Instances For
A left adjoint preserves colimits.
See
Equations
- CategoryTheory.Adjunction.leftAdjointPreservesColimits adj = CategoryTheory.Limits.PreservesColimitsOfSize.mk
Instances For
Equations
- CategoryTheory.Adjunction.isEquivalenceReflectsColimits E = CategoryTheory.Limits.ReflectsColimitsOfSize.mk
Equations
- CategoryTheory.Adjunction.isEquivalenceCreatesColimits H = CategoryTheory.CreatesColimitsOfSize.mk
Transport a HasColimitsOfShape
instance across an equivalence.
Transport a HasColimitsOfSize
instance across an equivalence.
The left adjoint of Cones.functoriality K G : Cone K ⥤ Cone (K ⋙ G)
.
Auxiliary definition for functorialityIsRightAdjoint
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The unit for the adjunction for Cones.functoriality K G : Cone K ⥤ Cone (K ⋙ G)
.
Auxiliary definition for functorialityIsRightAdjoint
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The counit for the adjunction for Cones.functoriality K G : Cone K ⥤ Cone (K ⋙ G)
.
Auxiliary definition for functorialityIsRightAdjoint
.
Equations
- CategoryTheory.Adjunction.functorialityCounit' adj K = CategoryTheory.NatTrans.mk fun (c : CategoryTheory.Limits.Cone K) => CategoryTheory.Limits.ConeMorphism.mk (adj.counit.app c.pt)
Instances For
The functor Cones.functoriality K G : Cone K ⥤ Cone (K ⋙ G)
is a right adjoint.
Equations
- One or more equations did not get rendered due to their size.
Instances For
A right adjoint preserves limits.
See
Equations
- CategoryTheory.Adjunction.rightAdjointPreservesLimits adj = CategoryTheory.Limits.PreservesLimitsOfSize.mk
Instances For
Equations
- CategoryTheory.Adjunction.isEquivalenceReflectsLimits E = CategoryTheory.Limits.ReflectsLimitsOfSize.mk
Equations
- CategoryTheory.Adjunction.isEquivalenceCreatesLimits H = CategoryTheory.CreatesLimitsOfSize.mk
Transport a HasLimitsOfShape
instance across an equivalence.
Transport a HasLimitsOfSize
instance across an equivalence.
auxiliary construction for coconesIso
Equations
- CategoryTheory.Adjunction.coconesIsoComponentHom adj Y t = CategoryTheory.NatTrans.mk fun (j : J) => (adj.homEquiv (K.toPrefunctor.obj j) Y) (t.app j)
Instances For
auxiliary construction for coconesIso
Equations
- CategoryTheory.Adjunction.coconesIsoComponentInv adj Y t = CategoryTheory.NatTrans.mk fun (j : J) => (adj.homEquiv (K.toPrefunctor.obj j) Y).symm (t.app j)
Instances For
auxiliary construction for conesIso
Equations
- CategoryTheory.Adjunction.conesIsoComponentHom adj X t = CategoryTheory.NatTrans.mk fun (j : J) => (adj.homEquiv X.unop (K.toPrefunctor.obj j)) (t.app j)
Instances For
auxiliary construction for conesIso
Equations
- CategoryTheory.Adjunction.conesIsoComponentInv adj X t = CategoryTheory.NatTrans.mk fun (j : J) => (adj.homEquiv X.unop (K.toPrefunctor.obj j)).symm (t.app j)
Instances For
When F ⊣ G
,
the functor associating to each Y
the cocones over K ⋙ F
with cone point Y
is naturally isomorphic to
the functor associating to each Y
the cocones over K
with cone point G.obj Y
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
When F ⊣ G
,
the functor associating to each X
the cones over K
with cone point F.op.obj X
is naturally isomorphic to
the functor associating to each X
the cones over K ⋙ G
with cone point X
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- CategoryTheory.Functor.instPreservesColimitsOfShape F = CategoryTheory.Limits.PreservesColimitsOfSize.preservesColimitsOfShape
Equations
- CategoryTheory.Functor.instPreservesColimits F = CategoryTheory.Limits.PreservesColimitsOfSize.mk
Equations
- CategoryTheory.Functor.instPreservesLimitsOfShape F = CategoryTheory.Limits.PreservesLimitsOfSize.preservesLimitsOfShape
Equations
- CategoryTheory.Functor.instPreservesLimits F = CategoryTheory.Limits.PreservesLimitsOfSize.mk