Gary is strong. Gary is big. Harry is short. Harry is thin. Bob is kind. Alan is rough. Alan is bad. If someone is not huge then they are rough. If someone is not sad then they are quiet. If someone is kind then they are smart. If someone is smart and not poor then they are wealthy. If someone is rough and not huge then they are dull. If someone is short and thin then they are poor. If someone is poor and not smart then they are bad. All quiet people are nice. 
Gary is not dull.