In mathematics, Jacob's ladder is a surface with infinite genus and two ends. It was named after Jacob's ladder by Étienne Ghys, because the surface can be constructed as the boundary of a ladder that is infinitely long in both directions.
Walczak, Paweł (2004), Dynamics of foliations, groups and pseudogroups, Instytut Matematyczny Polskiej Akademii Nauk. Monografie Matematyczne (New Series) [Mathematics Institute of the Polish Academy of Sciences. Mathematical Monographs (New Series)], vol.64, Birkhäuser Verlag, ISBN978-3-7643-7091-6, MR2056374