Maestro n° 102 : Page 78 - Gr 75
L7C7 =1= L7C5 -1- L3C5 =1= L2C6 -1-8- L2C6 =8= L2C2 -8- L9C2 =8= L9C8 donc L9C8 ≠ 1 et L7C7 ≠ 8