 Let \(\mathbf{H}\) denote a complex Hilbert space and let \(\mathcal{A}_{\mathbf{H}}\) denote the collection of (unordered) orthonormal bases of \(\mathbf{H}\). Thus, the outcome-space \(X\) of \(\mathcal{A}_{\mathbf{H}}\) will be the unit sphere of \(\mathbf{H}\). Note that if \(u\) is any unit vector of \(\mathbf{H}\) and \(E \in \mathcal{A}_{\mathbf{H}}\) is any orthonormal basis, we have 