Uniqueness of adjoints #
This file shows that adjoints are unique up to natural isomorphism.
Main results #
Adjunction.natTransEquivandAdjunction.natIsoEquivIfF ⊣ GandF' ⊣ G'are adjunctions, then there are equivalences(G ⟶ G') ≃ (F' ⟶ F)and(G ≅ G') ≃ (F' ≅ F). Everything else is deduced from this:Adjunction.leftAdjointUniq: IfFandF'are both left adjoint toG, then they are naturally isomorphic.Adjunction.rightAdjointUniq: IfGandG'are both right adjoint toF, then they are naturally isomorphic.
If F ⊣ G and F' ⊣ G' are adjunctions, then giving a natural transformation G ⟶ G' is the
same as giving a natural transformation F' ⟶ F.
Equations
- One or more equations did not get rendered due to their size.
Instances For
If F ⊣ G and F' ⊣ G' are adjunctions, then giving a natural isomorphism G ≅ G' is the
same as giving a natural transformation F' ≅ F.
Equations
- One or more equations did not get rendered due to their size.
Instances For
If F and F' are both left adjoint to G, then they are naturally isomorphic.
Equations
- adj1.leftAdjointUniq adj2 = ((adj1.natIsoEquiv adj2) (CategoryTheory.Iso.refl G)).symm
Instances For
If G and G' are both right adjoint to F, then they are naturally isomorphic.
Equations
- adj1.rightAdjointUniq adj2 = (adj1.natIsoEquiv adj2).symm (CategoryTheory.Iso.refl F)