Maestro n° 103 : Page 49 - Gr 46
r7c3 =6= r3c3 -6-7- r3c3 =7= r3c7 -7-2- r3c7 =2= r7c7 -2- r9c9 =2= r9c2 => r7c3 ≠ 2 and r9c2 ≠ 6