∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {D : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} D]
  {F : CategoryTheory.Functor C D} {R : CategoryTheory.Functor Dᵒᵖ RingCat} {S : CategoryTheory.Functor Cᵒᵖ RingCat}
  (φ : S ⟶ F.op.comp R),
  PresheafOfModules.pushforwardComp (CategoryTheory.CategoryStruct.id S) φ =
    (PresheafOfModules.pushforward φ).isoWhiskerLeft (PresheafOfModules.pushforwardId S) ≪≫
      (PresheafOfModules.pushforward φ).rightUnitor