Maestro n° 085 : Page 71 - Gr 68
L1C2 =1= L9C2 -1-5- L9C2 =5= L7C1 -5-7- L7C1 =7= L7C5 -7- L9C5 =7=3= L9C5 -3- L9C3 =3=1= L9C3 donc L1C3 et L9C2 ≠ 1