                 delta = m_r_solver.m_lower_bounds[j] - x;                     x = m_r_solver.m_lower_bounds[j];                 }                 break;             case column_type::fixed:                 delta = m_r_solver.m_lower_bounds[j] - x;                 x = m_r_solver.m_lower_bounds[j];                 break;              default:                 l