Let $I$ be an D1128: Inner product space over $\mathbb{C}$ such that
| (i) | $0_I$ is a D737: Zero vector in $I$ |
| (ii) | $\langle \cdot, \cdot \rangle$ is the D34: Inner product in $I$ |
| (iii) | $x \in I$ is a D1129: Vector in $I$ |
Then
\begin{equation}
\langle x, 0_I \rangle
= \langle 0_I, x \rangle
= 0
\end{equation}