Read the Sudoku help page for the rules, and the techniques potentially required to solve BrainBashers Sudoku.
An XYZ-Wing is a very advanced technique which can eliminate certain candidates from squares and is a very similar technique to XY-Wing.
We are looking for three squares. This time the first square contains XYZ and we require a buddy of this square to contain XZ. We then require another buddy of the XYZ square to contain YZ.
Any squares that are buddies to all three squares, XYZ, XZ & YZ cannot contain Z. Why? Because no matter which way around the digits go, the Z will be in one of the three squares.
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