Remark: Known transfer phase

If $q=\sqrt{\eta }{e}^{\mathrm{i}\alpha }$, the uncorrected occupied column has coefficients $q^2,q\sqrt{t},-q\sqrt{t},t$. The accessible correction $e^{-\mathrm{i}\alpha N_R}$ yields Definition def:extractor. This phase correction is fixed independently of the logical input. Its implementation is a separate certification obligation.