Maestro n° 087 : Page 26 - Gr 23
L4C1 =7= L7C1 -7-2- L7C1 =2= L8C3 -2-4- L8C3 =4= L9C3 -4- L9C5 =4= L7C5 -4- L7C8 =4=6= L7C8 -6- L7C2 =6=7= L7C2 donc L5C2 et L7C1 ≠ 7