  Let $(X, \mathcal{B}, \mu, T)$ be a dynamical system where $X$ is a compact
metric space with Borel $\sigma$-algebra $\mathcal{B}$, and $\mu$ is a
probability measure that's ergodic with respect to the homeomorphism $T : X \to
X$. We study the following differentiation problem: Given $f \in C(X)$ and $F_k
\in \mathcal{B}$, where $\mu(F_k) > 0$ and $\mu(F_k) \to 0$, when can we say
that $$\lim_{k \to \infty} \frac{\int_{F_k} \left( \frac{1}{k} \sum_{i = 0}^{k
- 1} T^i f \right) \mathrm{d} \mu}{\mu(F_k)} = \int f \mathrm{d} \mu ? $$
