Here is part of my private response to Alan:
It's not a strictly kosher solution, however, because there are definitely two non-triangular interstices.
You have correctly guessed that I intended only tricuspid voids, and assumed that no other solution would fit. [...] This puzzle is probably more evil than you think. The "oval" has no axis of symmetry, and the tolerances are very close. In the intended solution, the pieces slide in easily, but it is difficult to insert a strip of paper between a piece and the edge of the cavity. [The puzzle is nearly 1' in diameter.] So I had to try all four reflections of your solution, and one very nearly fit, but not quite. Sadly, however, I woke up today realizing how I had wasted space, and found several bogus solutions inside five minutes. Back to the drawing board. So far, my only disk puzzle where the only solution is tricuspid is the circular http://gosper.org/Huddle.RTF . This was only Arnold Laidanegger. The real Dozenegger is still in the gym. --rwg --------------------------------- Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase.