Suppose that $g$ is of class $\mathscr{C}^1$. Show that $g'$ is bounded. Deduce that $f$ is of class $\mathscr{C}^1$, that $f'$ is bounded and uniformly continuous and that for all $x \in \mathbb{R}$,
$$f'(x) = g'(x) + \sum_{i=0}^{+\infty} p_i f'\left(x - x_i\right)$$