So f of C equals four, so that would be a case where L is equal to four. So there's at least one C in this interval such that f of C is equal to four. We could say that, but that's not exactly what they're saying here. F of C could be four for at least one C, not in this interval. Remember, the C is our X. This is our X right over here. So the C is going to be in this interval.