∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {X Y : C}
  [inst_1 : HomotopicalAlgebra.CategoryWithWeakEquivalences C] (P : HomotopicalAlgebra.PathObject Y)
  [(HomotopicalAlgebra.weakEquivalences C).HasTwoOutOfThreeProperty]
  [(HomotopicalAlgebra.weakEquivalences C).ContainsIdentities] {f₀ f₁ : X ⟶ Y} (h : P.RightHomotopy f₀ f₁),
  HomotopicalAlgebra.WeakEquivalence f₀ ↔ HomotopicalAlgebra.WeakEquivalence f₁