Locked Pairs
Points. A Locked Pair is a Naked Pair where both cells are
in a box line intersection. Because the cells (truths) are covered by both a
line and a box, it can cause eliminations in both. This is a classic example
of a truth that can be covered in more than one way.
Locked Pair, Rows. The
two cells in box 5 are also locked in row 5, thus eliminating both digit 1
and digit 8 in both the box and the row.


Locked Pair, Columns.
The two cells in box 7 are also locked in column 6, thus eliminating both
digit 2 and digit 7 in both the box and the column.


Locked Pair, Columns.
The two cells in box 9 are also locked in column 8, thus eliminating both
digit 2 and digit 8 in both the box and the column. The link to candidates
graphic option is off.


