∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {D : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} D]
  {F : CategoryTheory.Functor Cᵒᵖ Dᵒᵖ} {G : CategoryTheory.Functor Dᵒᵖ Cᵒᵖ} (h : G ⊣ F),
  h.unop.counit = CategoryTheory.NatTrans.unop h.unit