s="line"><a name="l00116"></a><span class="lineno">  116</span>&#160; </div>
<div class="line"><a name="l00117"></a><span class="lineno">  117</span>&#160;  <span class="comment">// NOTE: this is a bit heuristic: we assume that if we evaluate</span></div>
<div class="line"><a name="l00118"></a><span class="lineno">  118</span>&#160;  <span class="comment">// f at a primitive root of unity, then we get something that well</span></div>
<div class="line"><a name="l00119"></a><span class="lineno">  119</span>&#