"Symmys" (from "symmetry") are built by taking a 5-piece "unit" and reflecting it repeatedly. When you place copies of "units" next to each other, the pieces at the junction become fewer and larger. Curvy lines are added and removed to make the puzzle interlock and to make the piece count prime. (Mouse over the cutting pattern above to see what the 3 row 4 column grid looked like before the edits were made.) Note: The piece labeled beta is shown between the cutting pattern and the full puzzle. "Symmys" are cut in pairs and are fun to assemble simultaneously.

http://www.primepuzzle.com/symmys_chatfield_hollow.html   Wednesday, June 15, 2005