Maestro n° 103 : Page 73 - Gr 70
r8c1 =8= r9c1 -8- r9c5 =8= r5c5 -8-6- r5c5 =6= r5c4 -6-7- r5c4 =7= r8c4 => r8c1 ≠ 7 and r8c4 ≠ 8