Maestro n° 102 : Page 86 - Gr 83
L8C9 -7- L8C4 =7=1= L8C4 -1- L6C4 =1= L6C7 -1-6- L6C7 =6= L6C3 -6- L4C1 =6= L9C1 -6- L9C9 =6=7= L9C9 -7- L8C9 donc L8C9 ≠ 7