Maestro n° 087 : Page 83 - Gr 80
L5C7 -1- L5C3 =1= L3C3 -1- L3C8 =1=6= L3C8 -6- L4C8 =6= L4C9 -6-5- L4C9 =5= L5C7 donc L5C7 ≠ 1