On Tue, 21 Aug 2007, Diane Colley wrote:
You're never more than 4 moves away, I know that. I'll get a proof of that worked up.
I would be very interested in seeing that. Off the top of my head, I can't think of any pairs of configurations that disprove it (although the starting configurations are 4 moves apart, which lends some credence to the theory.)
-- Dale Sheldon dales@xxxxxxxxxxxxxxxxx