ineno">  214</span>&#160; </div>
<div class="line"><a name="l00220"></a><span class="lineno">  220</span>&#160; </div>
<div class="line"><a name="l00221"></a><span class="lineno">  221</span>&#160;  <span class="comment">// NOTE: this is a bit heuristic: we assume that if we evaluate</span></div>
<div class="line"><a name="l00222"></a><span class="lineno">  222</span>&#160;  <span class="comment">// f at a primitive root of unity, then we get something that</span></div>
<div class="line"><a name="l00223"></