 So let's take a look at something that's similar to problem 1.6. So this is to draw circles representing sets where a certain group of conditions has to be met. And in this particular case, let's suppose I'm going to take something where every element of A is an element of B, but no element of A is an element of C. So we might experiment by drawing different circles for the sets A and B first and seeing if we can find a circle that's appropriate for set C. Again, once you've been shown how to solve a problem, you will never again have the opportunity to solve the problem. And this doesn't apply to this problem here. Only it applies to every problem that arises that's in any way shape or form similar to this. So if you continue to watch the video without trying to solve the problem first, you will never get another chance to solve this or any other problem that's similar to it. The best you'll be able to do is to copy somebody else's solution. So try to experiment with some possibilities before continuing to watch the video. So maybe I'll draw some circles and, well, that doesn't work. So I draw some circles and, well, if I draw the circles this way, some elements of A might actually be elements of B. And I need every element of A to be an element of B. So it's possible for some elements of A to not be an element of B. Well, maybe I'll draw the circles this way. And again, this doesn't work because no element of A can be an element of B. And so every element of A has to be an element of B. This doesn't work. So how about this? So here, everything in A has to be in B as well. So every element of A is an element of B. That's exactly what we want. Well, we need that third set C. So let's see if I can draw a third circle. So let's try and draw C. And again, I'll try some random drawings of that set C and C where it fits. So maybe I'll draw something like this. And, well, I need to make sure that no element of A is an element of C. And here, I can have something that is an element of A and also an element of C. So this circle doesn't work. Maybe I'll try to draw the circle there. Well, here, no element of A can be an element of C. So that works, except there is something we've added here, which is that we've also added that no element of B can also be an element of C. And that isn't required. We don't require that. And it also means that because it's not required, this picture is not a sufficiently generic picture. So we're going to slide C over here. So now we still have no element of A can possibly be an element of C, but we're allowing for the possibility that B and C might have some elements in common. And so there's our picture.