Merve Cayli, Ayse Gul Karatop, Emrah Kavlak, Hakan Kaynar
                               Ferhan Ture, and Esra Erdem

               Sabanci University, Faculty of Engineering and Natural Sciences


We study four challenging grid puzzles, Nurikabe, Heyawake, Masyu, Bag Puzzle, 
interesting for answer set programming (ASP) from the viewpoints of representation 
and computation: they show expressivity of ASP, they are good examples of a representation 
methodology, and they form a useful suite of benchmarks for evaluating/improving 
computational methods for nontight programs.