∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X : C} {S : CategoryTheory.Sieve X}
  {P : CategoryTheory.Functor Cᵒᵖ (Type u_1)} (t : { x // x.Compatible }) (Y Z : Cᵒᵖ) (g : Y ⟶ Z),
  (CategoryTheory.CategoryStruct.comp (S.functor.map g) fun f => ↑t ↑f ⋯) =
    CategoryTheory.CategoryStruct.comp (fun f => ↑t ↑f ⋯) (P.map g)