Number Line Collection Slitherlink: 250 Medium to Hard Sli-Lin Logic Puzzles 7x7, Book 10, (Paperback)

Slitherlink is played on a rectangular lattice of dots. Some of the squares formed by the dots have numbers inside them. The objective is to connect horizontally and vertically adjacent dots so that the lines form a single loop with no loose ends. In addition, the number inside a square represents how many of its four sides are segments in the loop.