Puzzle by Nikoli W Heyawake

This is a progressive puzzle which you can comfortably enjoy working out using logic. "Heyawake" is a puzzle in which you fill in the spaces according to the rules. It's called "heyawake" ("split rooms") because the face of the board is divided into rooms. This puzzle first appeared in 1992, but a plethora of solutions have been developed, allowing for a very progressive puzzle. Each time you discover a new strategic move, your skills of solution will improve....