Definition:Quaternion Conjugate/Quaternion Conjugation

Definition
The operation of quaternion conjugation is the mapping:
 * $\overline \cdot: \mathbb H \to \mathbb H: \mathbf x \mapsto \overline{\mathbf x}$.

where $\overline{\mathbf x}$ is the quaternion conjugate of $x$.

That is, it maps a quaternion to its quaternion conjugate.