Example:

And since finite subsets of the real numbers are not open, this shows that intersections of open sets need not be open.

But, there's more...

Proof

Analysis WebNotes by John Lindsay Orr.
Comments to the author: jorr@math.unl.edu

All contents copyright (C) 1996 John L. Orr
University of Nebraska--Lincoln
All rights reserved

Last modified: May 1996