Dave is blue. Dave is nice. Dave is quiet. Dave is rough. Gary is blue. Gary is green. Gary is nice. Gary is quiet. Gary is rough. Gary is young. Smart things are rough. If something is nice then it is green. All smart, green things are young. All rough, quiet things are green. Quiet things are blue. If something is quiet and green then it is smart. If something is young then it is quiet. Smart, nice things are green.
Dave is not rough.