Maestro n° 101 : Page 60 - Gr 57
L1C7 =1= L1C9 -1- L9C9 =1= L9C3 -1-6- L9C3 =6= L7C3 -6-5- L7C3 =5= L7C8 -5-8- L7C8 =8= L7C7 donc L7C7 ≠ 1 et L1C7 ≠ 8