a a x1 b c x1 b b x1 c d x1 b x1 a x1 c c x1 d f x1 d d x1 f f f x1 d x1 b x1 f f x1 g a x1 g g x1 a x1 a 1 b 1 c 1 d 1 f 1 g 1 FULL ./SRS/Zantema/z112.srs