This is part of the exercise 2.13 in the book Foundations of Machine Learning (page 28). You can refer to chapter 2 for the notations.
Consider a family of concept classes $\left\{\mathcal{C}_{s}\right\}_{s}$ where $\mathcal{C}_{s}$ is the set of concepts in $\mathcal{C}$ with size at most $s...
This is an inequality on page 36 of the book Foundations of Machine Learning, but the author only states it without proof.
$$
\mathbb{P}\left[\left|R(h)-\widehat{R}_{S}(h)\right|>\epsilon\right] \leq 4 \Pi_{\mathcal{H}}(2 m) \exp \left(-\frac{m \epsilon^{2}}{8}\right)
$$
Here the growth function...