And once again, A and B don't both have to be positive. They could both be negative. One could be, A could be negative, B could be positive, and maybe in this situation, then F of A and F of B, it could also be positive or negative. But let's take a situation where this is F of A. So that right over there is F of A. This right over here is F of B. F of B. And once again, we're saying F is a continuous function.