class="lineno">  192</span>&#160; </div>
<div class="line"><a name="l00199"></a><span class="lineno">  199</span>&#160; </div>
<div class="line"><a name="l00200"></a><span class="lineno">  200</span>&#160;  <span class="comment">// NOTE: this is a bit heuristic: we assume that if we evaluate</span></div>
<div class="line"><a name="l00201"></a><span class="lineno">  201</span>&#160;  <span class="comment">// f at a primitive root of unity, then we get something that</span></div>
<div class="line"><a name="l0