View 3279_counting1.mw on MapleNet The program above has a bug. From time to time it ends up with an error message. I need help fixing it. It cannot evaluate a boolean function (somewhere in there) but if one runs it again it may proceed all the way to the end. I was wandering if you guys have encountered something similar with Maple and if anyone can give me a hint about how to get around this. The way I overvcome this problem now is really silly: I just make it run from the last step where it got stuck and with a few trials it goes all the way to the end. Once it comes out of the errors part it produces the correct answer (that is why I would like to salvage it).