477         Vector2s essential2;  in step()  local
484         essential2 = hr.template bottomRows<2>();  in step()
486 …m_S.template middleRows<3>(k).rightCols(dim-fc).applyHouseholderOnTheLeft(essential2, tau, m_works…  in step()
487 …m_T.template middleRows<3>(k).rightCols(dim-fc).applyHouseholderOnTheLeft(essential2, tau, m_works…  in step()
489 …     m_Q.template middleCols<3>(k).applyHouseholderOnTheRight(essential2, tau, m_workspace.data());  in step()
496         essential2 = hr.template bottomRows<2>();  in step()
501           tmp = m_S.template middleCols<2>(k).topRows(lr) * essential2;  in step()
504           m_S.template middleCols<2>(k).topRows(lr) -= (tau*tmp) * essential2.adjoint();  in step()
506           tmp = m_T.template middleCols<2>(k).topRows(lr) * essential2;  in step()
509           m_T.template middleCols<2>(k).topRows(lr) -= (tau*tmp) * essential2.adjoint();  in step()
515           tmp = essential2.adjoint()*(m_Z.template middleRows<2>(k));  in step()
518           m_Z.template middleRows<2>(k) -= essential2 * (tau*tmp);  in step()