Another extension is that inequalities can be used in place of numbers denoting range: thus, while R4 is a piece that moves like a rook, but only up to four squares, R(2≤"n"≤4) is a piece that moves like a rook, but only two, three, or four squares. Further, p"n" refers to cannon-like pieces that can jump at most "n" pieces along their path, and pp means the same as p∞ (just as WW is synonymous with W∞, both meaning a rook). Finally, x stands for "shooting": the xK for instance can pass its turn (shooting empty squares), or it can shoot (capture) any adjacent enemy piece without moving.