  The geometry of hypersurfaces is generalized to pseudo-hypersurfaces, which
are defined by Pfaff equations. The general methods are then applied to
modeling the kinematics of motion constrained by a single linear, non-holonomic
constraint. They are then applied to the example of a charge moving in an
electromagnetic field, and the Lorentz equation of motion is shown to represent
a geodesic that is constrained to lie in a pseudo-hypersurface that is defined
by the potential 1-form.
