||A W-wing consists of two
cells that cannot see each other (shown in blue). They contain
candidates X & Y. These cells are the wings (or
pincers) of the W wing..
Unlike the XY wing and XYZ wing, there isn't a single base (or pivot).
A W-wing has two base cells (yellow) where:
This forces the Y candidate to be present in at least one of the wings
(candidate 1 in the blue cells).
The candidate 1 (Y) can be removed from any cell that is
visible to both wings (like r2c7).
- They are strongly
linked to each other by candidate X (5 in this example)
- Each base cell (yellow) is visible to one of the
wings (links between base and pincers can be weak or strong)
(Did you notice that a W-wing is also an