Date: 22 Jul 1980 1211-PDT (Tuesday) From: Mike at UCLA-SECURITY (Michael Urban) Subject: Yet another checkerboard To: cube-lovers at mit-mc Nobody has mentioned (or discovered?) the fully-interlocked checkerboard pattern obtained by applying the Pons Asinorum transformation to the Plummer's Cross as suggested by Greenberg during his description thereof, and then performing a few triple-center swaps (unfortunately, I was playing rather randomly with the 3c swaps at the time and must leave them as an "exercise for the reader"). The six colors are interlocked in pairs of AB, BC, CD, DE, EF, and FA on each checkerboard. Quite mysterious. Mike -------