And so as we approach from the left, as X approaches C from the left, we actually have a situation where this expression right over here is going to approach negative infinity. And if we approach from the right, if we approach with X as large as in C, well this is our X comma F of X. So we have a positive slope. And then as we get closer, it gets more positive. More positive approaches positive infinity. But either way, it's not approaching a finite value. And one side is approaching positive infinity and the other side is approaching negative infinity.