Maestro n° 097 : Page 54 - Gr 51
L7C9 =7= L7C5 -7-5- L7C5 =5= L7C1 -5- L8C3 =5= L2C3 -5-6- L2C3 =6= L2C4 -6- L9C4 =6=7= L9C4 donc L7C5 et L9C9 ≠ 7