mules — a lounging slipper that covers the toes and instep or only the instep.
pools — Also called pocket billiards. any of various games played on a pool table with a cue ball and 15 other balls that are usually numbered, in which the object is to drive all the balls into the pockets with the cue ball.
rules — a principle or regulation governing conduct, action, procedure, arrangement, etc.: the rules of chess.
schools — a large number of fish, porpoises, whales, or the like, feeding or migrating together.
tools — Technology of Object-Oriented Languages and Systems
