fact: Definition ooextendable_contr {A B : Type} (C : B -> Type) (f : A -> B) `{forall b, Contr (C b)} : ooExtendableAlong f C := fun n => extendable_contr n C f.
imports: HoTT.Basics HoTT.Types Equiv.PathSplit PathAny Cubical.DPath Cubical.DPathSquare Colimits.Coeq Colimits.MappingCylinder