- ➊ Blacken some cells of the diagram and
- ➋ draw a single closed loop which does not cross or touch
- ➌ The sections of the loop run horizontally and vertically
between the center points of
orthogonally adjacent cells.
- ➍ The loop must visit all empty white cells exactly once.
- ➎ The number in a cell indicates the number of black cells in
the direction the corresponding arrow points to (up to the edges of the
diagram, not up to the next numbered cell). There may exist some black cells
no arrow points to.
- ➏ Numbered cells are never painted black.
- ➐ Black cells must not be orthogonally adjacent.
- ➑ Crossed cells do not count as black cells and cannot be
visited by the loop.