a b b x1 P a b x1 a P x1 P a x x1 a x x1 x a x1 b P x1 b Q x1 Q x x1 a Q x1 Q a x1 b b a x1 a 1 b 1 P 1 x 1 Q 1 FULL ./SRS/Waldmann/jw3.srs