  <HR> This work is in  connection with a project on  <A HREF="http://www.cs.washington.edu/homes/anderson/research.html"> data structures</A> by Prof.  <A HREF="http://www.cs.washington.edu/homes/anderson">Richard Anderson</A>.   A <A HREF="http://www.cs.washington.edu/homes/anderson/papers/tree.ps">draft paper</A> is also available. <P>
