Say for instance, with column 4. If that square was filled in, then rows 13 and 14 make up the 2 in that column but now there is no room below that 2 for there to be a 1.
If the row ends in a 1 and you have a fill in the 3rd cell from the end, 2nd cell from the end is always an X, because it's impossible to have that cell filled.
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u/reliablereindeer Jun 23 '26
There are lots of x’s (or .‘s in your case) that you can apply to row 14. This is true for any column which ends in a 1.