And then you take another, and then you take that output and input it into another function that we could call v. And what does v do? Well, it takes the natural log of whatever the input is. In this case, in the case of f, or in the case of how I've just diagrammed it, v is taking the natural log, the input happens to be square root of x. So it outputs the natural log of the square root of x. If we wanted to write v with x as an input, we would just say, well, that's just the natural log. That is just the natural log of x. And as you can see here, f of x, and I color-coded it ahead of time, is equal to, f of x, f of x is equal to the natural log of the square root of x.