A local extreme vertex is the local
maximum
for the
height function
on *M * in some direction, and a vertex that is not
locally extreme is a
saddle point
for *every* height function on *M*.

The extreme vertices can be used as a convenient means of describing tightness for polyhedral surfaces.

* 11/1/94 dpvc@geom.umn.edu -- *

*The Geometry Center*