Let $a \in (0, 1)$ be a D5407: Positive real number such that

(i)	$b \in 2 \mathbb{Z} + 1$ is an D7: Odd integer
(ii)	\begin{equation} a b > 1 + \frac{3 \pi}{2} \end{equation}

The Weierstrass function with respect to $(a, b)$ is the D4364: Real function \begin{equation} \mathbb{R} \to \mathbb{R}, \quad x \mapsto \sum_{n = 0}^{\infty} a^n \cos(b^n \pi x) \end{equation}