Selecting a small picture will enlarge it.
The segment of
self-intersection is visible. The top endpoint of the segment is a
"pinch point."
The pinch point is
visible from above. Part of the self-intersection is visible.
Color is assigned according to v parameter.
This is the
same view depicted in the first picture. The coloring helps to
illustrate that the rectangle is intersecting itself, not being
creased in the middle.
This is the same view
depicted in the second picture.
Whitney's Umbrella seen
from underneath.
Comments to: webmaster@www.geom.uiuc.edu
Created: Jul 6 1995 ----
Last modified: Fri Aug 11 18:06:01 1995
Copyright © 1995 by
The Geometry Center,
all rights reserved