Maestro n° 103 : Page 86 - Gr 83
r1c8 =5= r7c8 -5- r8c7 =5= r8c1 -5-1- r8c1 =1= r8c9 -1- r9c8 =1= r2c8 -1-9- r2c8 =9= r1c8 => r12c8 ≠ 2 and r12c8 ≠ 7