Generically, this means that three parts of the surface pass through
a single point in much the same way that the *xy*-, *xz*- and
*yz*-coordinate planes intersect at the origin.

For mappings of surfaces into space, triple points are generally isolated.

The number of triple points in an immersion is related to the Euler characteristic of the surface.

* 8/12/94 dpvc@geom.umn.edu -- *

*The Geometry Center*