Maestro n° 100 : Page 72 - Gr 69
L9C7 =7= L1C7 -7-3- L1C7 =3= L1C8 -3- L6C8 =3=7= L6C8 -7- L9C8 =7=9= L9C8 donc L9C8 ≠ 7 et L9C7 ≠ 9