Let $I$ be an D1128: Inner product space such that

(i)	$\langle \cdot, \cdot \rangle$ is the D34: Inner product on $I$
(ii)	$x, y \in I$ are each a D1129: Vector in $I$

Then $(x, y)$ is an orthogonal vector pair in $I$ if and only if \begin{equation} \langle x, y \rangle = 0 \end{equation}