Maestro n° 097 : Page 61 - Gr 58
L1C3 =2= L1C2 -2- L5C2 =2= L5C9 -2- L4C9 =2= L4C5 -2- L6C6 =2= L2C6 -2- L2C4 =2= L7C4 donc L7C3 ≠ 2