- Draw a single closed loop along the grid lines that does not visit any
grid point more than once, but does not necessarily visit all grid points
- A number in a cell indicates how many of the four grid lines surrounding
that cell are used by the loop.
- For a cell without a number the loop can use any number of
surrounding grid lines.
Additional Rules:
Inside of the loop areas of size 2x2 cells are not allowed (outside of the
loop areas of size 2x2 are permitted).
Regeln