Maestro n° 103 : Page 50 - Gr 47
r5c8 -6- r5c2 =6=1= r5c2 -1- r1c2 =1= r1c9 -1- r2c7 =1= r8c7 -1-6- r8c7 =6= r8c8 -6- r5c8 => r5c8 ≠ 6