{A B} (f : A -> B) (C : Cyl f -> Type) (ext : ooExtendableAlong cyl C) : ooExtendableAlong cyl C := fun n => cyl_extendable n f C (ext n).
Require Import HoTT.Basics HoTT.Types. Require Import Equiv.PathSplit Homotopy.IdentitySystems. Require Import Cubical.DPath Cubical.DPathSquare. Require Import Colimits.Coeq Colimits.MappingCylinder.