P781 xx | | —c | @pq | > || —c G 4 xp | > || —A÷ > —— x > | —c c
P781 p | > |= —c — > —c xx | > || —c — > | —c xq | > | —Gc
P781 p | > || —c | xp | > || —c G | x | |= —G
P781 ÷ pq | > || —c G > xq | > || —c G | pq x | | —cc—