∀ {R : Type u_1} [inst : CommRing R] (A : CategoryTheory.Mon (ModuleCat R)),
  CategoryTheory.CategoryStruct.comp (ModuleCat.ofHom { toFun := id, map_add' := ⋯, map_smul' := ⋯ })
      (ModuleCat.ofHom { toFun := id, map_add' := ⋯, map_smul' := ⋯ }) =
    CategoryTheory.CategoryStruct.id
      ((ModuleCat.MonModuleEquivalenceAlgebra.functor.comp (CategoryTheory.forget₂ (AlgCat R) (ModuleCat R))).obj A)