∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {D : Type u_4}
  [inst_1 : CategoryTheory.Category.{u_3, u_4} D] {L : CategoryTheory.Functor C D} {R : CategoryTheory.Functor D C}
  (h : L ⊣ R) {X Y : D} (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp (h.toMonad.map (R.map f))
      { A := R.obj Y, a := R.map (h.counit.app Y), unit := ⋯, assoc := ⋯ }.a =
    CategoryTheory.CategoryStruct.comp { A := R.obj X, a := R.map (h.counit.app X), unit := ⋯, assoc := ⋯ }.a (R.map f)