Let $I$ be an D1128: Inner product space over $\mathbb{C}$ such that

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

Then \begin{equation} \langle x, x \rangle \in \mathbb{R} \end{equation}