Maestro n° 087 : Page 70 - Gr 67
L2C1 =1=5= L2C1 -5- L2C3 =5= L5C3 -5- L5C7 =5= L9C7 -5-7- L9C7 =7= L2C7 -7- L2C9 =7=1= L2C9 donc L2C23 ≠ 1