An D995: Integer $a \in \mathbb{Z}$ is a 16-bit integer if and only if \begin{equation} \exists \, r_0, r_1, \ldots, r_{15} \in \{ 0, 1 \} : a = - r_{15} 2^{15} + \sum_{n = 0}^{14} r_n 2^n \end{equation}