∀ (C : Type u) [inst : CategoryTheory.Category.{v, u} C] (F : CategoryTheory.Functor C C) (X : C),
  (CategoryTheory.MonoidalCategoryStruct.leftUnitor F).hom.app X =
    CategoryTheory.CategoryStruct.id
      ((CategoryTheory.MonoidalCategoryStruct.tensorObj
            (CategoryTheory.MonoidalCategoryStruct.tensorUnit (CategoryTheory.Functor C C)) F).obj
        X)