A naked quad C1234, has also locked candidates 6 and 7 in 1 box, so you can exclude 6 in A2 and 7 in B3.
You can exclude first 3467 in C56789 with the naked quad and afterwards you can exclude 6 in A2 and 7 in B3 with locked candidates.
by creint » Wed Feb 06, 2019 5:24 pm
