="special">::</span><span class="identifier">numeric_limits</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;::</span><span class="identifier">epsilon</span><span class="special">());</span>
</pre>
<p>
        It's more usual though to have to define both the <span class="emphasis"><em>a</em></span>'s
        and the <span class="emphasis"><em>b</em></span>'s when evaluating special functions by continued
        fractions, for example the tan function is d