Before revision:  Beyond Riemannian {\em  geometry, there are many natural generalizations in the mathematical literature---areas such as Finsler geometry and spray geometry---but those generalizations are largely inaccessible, and as a result there remain few applications within robotics.
After revision:  Beyond Riemannian {\em geometry, there are many natural generalizations in the mathematical literature -- areas such as Finsler geometry and spray geometry---but those generalizations are largely inaccessible, and as a result there remain few applications within robotics.