I once implemented Minesweeper in Prolog and another time in Concurrent Clean. In both cases the minesweepers could optionally solve the easier cases for you. It was up to the level of "this square needs one more bomb, so these three squares may contain only one bomb so if that square needs two bombs, then the square over there must be a bomb, and the other will be in one of those two so this square is safe, ..." Shame I lost the code. I wonder though how much would it tell you about my understanding of objects ;-P