add the key math functions, especially those essential
        for statistics. After JM accepted and solved the difficult problems, not
        only numerically, but in full C++ template style, PAB implemented a few of
        the statistical distributions. PAB also tirelessly proof-read everything
        that JM threw at him (so that all remaining editorial mistakes are his fault).
      </p>
<p>
        Xiaogang Zhang worked on the Bessel functions and elliptic integrals for
        his Google Summer of 