∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : HomotopicalAlgebra.ModelCategory C] {A : C}
  [inst_2 : HomotopicalAlgebra.IsCofibrant A] (P P' : HomotopicalAlgebra.Cylinder A) [inst_3 : P'.IsGood],
  (P.trans P').π = CategoryTheory.Limits.pushout.desc P.π P'.π ⋯