span class="p">).</span><span class="nb">or</span><span class="p">.(</span><span class="n">ir2</span> <span class="o">/=</span> <span class="n">ir1</span><span class="p">)</span> <span class="p">)</span> <span class="k">then</span>  <span class="c">! if row or column index has changed</span>
            <span class="n">innz</span> <span class="o">=</span> <span class="n">innz</span> <span class="o">+</span><span class="mi">1</span>                         <span class="c">! a non-zero term is added</span>
  