Those of you with PCMacsyma 2.4 might enjoy www.tweedledum.com/rwg/tor7.mfe . Click on the last image, then the rocket icon. To tumble and zoom the moving image, click off the rocket, click the camera mount icon, Continuous Draw, then reclick the rocket. Control the speed with the movie camera icon. If you get sporadic gray frames, try reducing the section height or notebook width. If you wish to abuse it, the code is all there in the notebook. --rwg PS, rwg>>PS, I like Klarner's distinction: perfect packing -> tiling. JPropp>Can someone say what Klarner's distinction is? (I have used the

two phrases interchangeably in my own work.)

Sorry, probably everybody but me had it right all along. I was misusing packing to mean tiling.