We can say that B is a strict subset of A, because B is a subset of A, but it does not equal A, which means that there are things in A that are not in B. So we could even go further. And we could say that B is a strict, or sometimes said, a proper subset of A. And the way you do that is, essentially, you can almost imagine that this is kind of a less than or equal sign. And then you kind of cross out the equal part of the less than or equal sign. So this means a strict subset, which means everything that is in B is a member of A, but everything that's in A is not a member of B. So let me write this.