fact: Definition halfline_map {Y} {target_points:ℕ->Y} (s:target_paths target_points) : halfline -> Y.
imports: UniMath.Foundations.All UniMath.MoreFoundations.NullHomotopies UniMath.MoreFoundations.Nat UniMath.MoreFoundations.Notations UniMath.MoreFoundations.PartA