sing blocking.
        </li>
        <li>
          <b>DGBBQRS</b> solves A*X = B when A has been factored by DGBBQR2.
        </li>
        <li>
          <b>DGEBQR2</b> QR factors an M by N band matrix in GE format, with no blocking.
        </li>
        <li>
          <b>DGEBQRF</b> QR factors an M by N band matrix stored in GE format, with blocking.
        </li>
        <li>
          <b>DGEQRS</b> solves a linear system factored by DGEQRF.
        </li>
        <li>
          <b>DGEQRS_TWO</b> solves