∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {A : C}
  [inst_1 : HomotopicalAlgebra.CategoryWithWeakEquivalences C] (P : HomotopicalAlgebra.Cylinder A)
  [inst_2 : HomotopicalAlgebra.CategoryWithCofibrations C] [inst_3 : HomotopicalAlgebra.CategoryWithFibrations C]
  [(HomotopicalAlgebra.cofibrations C).RespectsIso] [inst_5 : CategoryTheory.Limits.HasBinaryCoproducts C]
  [P.IsVeryGood], P.symm.IsVeryGood