><em>a</em></span>
        and <span class="emphasis"><em>b</em></span> values in a continued fraction have different
        defining equations to the remaining terms, which may make the "_a"
        suffixed form more appropriate.
      </p>
<p>
        The generator type should be a function object which supports the following
        operations:
      </p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  Expression