Virtuose n° 121 : Page 76 - Gr 73
L8C1 -1- L2C1 =1= L2C6 -1- L5C6 =1=6= L5C6 -6- L8C6 =6= L8C8 -6-5- L8C8 =5= L8C1 donc L8C1 ≠ 1