- ➊ Blacken some cells of the diagram [paper] resp. color the
gray cells of the diagram black or white [interactively].
- ➋ The black cells divide the diagram in areas of
orthogonally contiguous white cells. White areas must not touch each other
- ➌ A cell with a number is always white; for each white area
belongs exactly one field with a number. The number in indicates how many
fields form the white area.
- ➍ The black cells must form horizontal or vertical stripes,
exactly one cell wide. If two stripes are
diagonally adjacent, they must be of different length.