% Francois Labelle & computer, January 30, 2004 % All 3 checkmate PG-2.5 with exactly 1 solution. % They are all SPGs. % Comment: % % SPG #1 is attributed to Juha M. Saukkola % SPG #3 is attributed to Joost de Heer and Richard Stanley % SPG #2 is a simple variant of #3 (Forsyth-Edwards Notation, followed by the same list in ascii diagrams) SPG-2.5: rnbqkbnr/ppppp2p/8/5PpQ/8/8/PPPP1PPP/RNB1KBNR rnbq1bnr/ppppkppp/8/4Q3/8/4P3/PPPP1PPP/RNB1KBNR rnbq1bnr/ppppkppp/8/4Q3/4P3/8/PPPP1PPP/RNB1KBNR _________________ _________________ _________________ | | | | | r n b q k b n r | r n b q . b n r | r n b q . b n r | | p p p p p . . p | p p p p k p p p | p p p p k p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . P p Q | . . . . Q . . . | . . . . Q . . . | | . . . . . . . . | . . . . . . . . | . . . . P . . . | | . . . . . . . . | . . . . P . . . | . . . . . . . . | | P P P P . P P P | P P P P . P P P | P P P P . P P P | | R N B . K B N R | R N B . K B N R | R N B . K B N R | |_________________|_________________|_________________|