Hidden Pair

Level: Intermediate

When two numbers can only go in the same two cells of a unit, remove the other candidates from those cells.

A Hidden Pair occurs when, within one unit, two numbers can only go in the same two cells.

Since those two numbers must split between those two cells, you can remove every other candidate from both cells. As a result, the two cells become a Naked Pair.

It's useful for cleaning up units that look complex due to many candidates, and it's easiest to understand as the paired version of the Hidden Single.

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