∀ {A : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} A] {B : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} B]
  {T : Type u₃} [inst_2 : CategoryTheory.Category.{v₃, u₃} T] {L : CategoryTheory.Functor A T}
  {R : CategoryTheory.Functor B T} {X : CategoryTheory.Comma L R},
  (CategoryTheory.CategoryStruct.id X).right = CategoryTheory.CategoryStruct.id X.right