Curse of the crystal skulls and other vanishing area puzzles
marianotomatis.it
marianotomatis.it
I'm having trouble finding Peter Tappan's "FuTILE Subtraction" from the citation
Look at the diagonal edges of the halves. They don't match up! I've put them together in Photoshop to make it clear: http://imgur.com/gsP6AxG When you put the two halves together, you don't get full cells. You get a crazy mishmash, because the height of one of the halves has been increased by 3/7ths of a cell-height. He replaced some pieces when he flipped the frame over.