©2017-2020 Michael P. Hitchman
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/
2018 Edition, compiled October, 2020
Cover image: Five geodesic paths between two points in a two-holed torus with constant curvature.