An D995: Integer $a \in \mathbb{Z}$ is an 8-bit integer if and only if \begin{equation} \exists \, r_0, r_1, \ldots, r_7 \in \{ 0, 1 \} : a = - r_7 2^7 + \sum_{n = 0}^6 r_n 2^n \end{equation}

An D995: Integer $a \in \mathbb{Z}$ is an 8-bit integer if and only if \begin{equation} \exists \, r_0, r_1, \ldots, r_7 \in \{ 0, 1 \} : a = r_0 + 2 r_1 + 4 r_2 + 8 r_3 + 16 r_4 + 32 r_5 + 64 r_6 - 128 r_7 \end{equation}