And f of b looks like it would have been our maximum value. So f of a would have been our maximum value. But we're not including a and b in the interval. This is an open interval. So you can keep getting closer and closer and closer to b, and keep getting higher and higher and higher values without ever quite getting to b. Because once again, we're not including the point b. Similarly, you could get closer and closer and closer to a and get smaller and smaller values, but a is not included in your set, in your consideration.