an class="emphasis"><em>h &gt; 1</em></span>.
        </li>
<li class="listitem">
          A version of T4 only when both T1 and T2 have failed to produce an accurate
          answer.
        </li>
<li class="listitem">
          Fallback to the Patefiled Tandy algorithm when all the above methods fail:
          this happens not at all for our test data at 100 decimal digits precision.
          However, there is a difficult area when <span class="emphasis"><em>a</em></span> is very
          close to 1 