{A B C : Type} (P : C -> Type) (f : A -> B) (g : B -> C) : ooExtendableAlong f (fun b => P (g b)) -> ooExtendableAlong (g o f) P -> ooExtendableAlong g P := fun extf extgf n => cancelR_extendable n P f g (extf 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.