 of the leading (N+P)-by-(N+M) part is used as
          internal workspace.

  LDBF    INTEGER
          The leading dimension of array BF.  LDBF &gt;= MAX(1,N+P).

</PRE>
<B>Tolerances</B>
<PRE>
  TOL     DOUBLE PRECISION
          A tolerance used in rank decisions to determine the
          effective rank, which is defined as the order of the
          largest leading (or trailing) triangular submatrix in the
          QR (or RQ) factorization with column (or row) pivoting
          whose estimated cond