This would be just the set with a single element in it, set 6. Now, let me ask another question. What would the relative complement of A in A be? This is the same thing as A minus A. This is literally saying let's take set A and then take all of the things that are in set A out of it. I start with a 5, but there's a 5 in set A so I have to take the 5 out. There's a 3, but there's a 3 in set A so I have to take a 3 out.