"k">               IF</span><span class="w"> </span><span class="p">(</span><span class="w"> </span><span class="n">X</span><span class="p">(</span><span class="n">i</span><span class="p">)</span><span class="o">==</span><span class="n">xprev</span><span class="w"> </span><span class="p">)</span><span class="w"> </span><span class="k">THEN</span>
<span class="k">                  </span><span class="n">Xr</span><span class="p">(</span><span class="n">i</span><span class="p">)</span><span class="w"> </span><