  </p>
<p>
      For h and a &gt; 0, T(h,a), gives the volume of an uncorrelated bivariate normal
      distribution with zero means and unit variances over the area between <span class="emphasis"><em>y
      = ax</em></span> and <span class="emphasis"><em>y = 0</em></span> and to the right of <span class="emphasis"><em>x
      = h</em></span>.
    </p>
<p>
      That is the area shaded in the figure below (Owens 1956).
    </p>
<p>
      <span class="inlinemediaobject"><img src="../../graphs/owens_integrat