Example of a Buried Double
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Buried Double:
Two Squares in the same
Row,
Column,
or Box
that contain the same two
Possibles - and the Possibles occur nowhere else
in that same Row, Column, or Box.In this example, the Buried Double is the two Squares containing the Possibles 1 and 4 (coloured cyan). These two Squares MUST contain 1 or 4. Therefore they cannot contain any other Possibles. The 2, 5 (two occurances), 6 and 8 outlined in orange are impossible solutions and can be removed.