On Fri, Dec 2, 2011 at 4:31 PM, David Nalesnik
<address@hidden> wrote:
(See attached file.)
Oops--that only accidentally works for your problem example since I goofed the filtering.
Replace the second definition of lst-2 in the file I last attached with this line and all should be well:
(lst-2 (remove (lambda (x) (interval-empty? (X-extent x))) lst-2))
-David