Pointing and Claiming

Pointing and claiming use the interaction between a box and a row or column.

Pointing Set

If all candidates for a digit in a box lie in one row or column, remove that digit from the rest of that row or column.

In the example above the 2s in box 2 are restricted to column 6. Remove 2 from the other cells of column 6 (red).

Box Line Reduction (Claiming)

If all candidates for a digit in a row or column lie in one box, remove that digit from the rest of that box.

In the example above the 2s in row 1 are restricted to box 2. Remove 2 from the other cells of box 2 (red).