an class="o">=</span><span class="n">where</span><span
            class="o">.</span><span class="n">suc</span><span class="p">)</span>
            <span class="n">where</span><span class="o">.</span><span class="n">right</span> <span
            class="o">=</span> <span class="n">node</span>
            <span class="k">if</span> <span class="n">where</span><span class="o">.</span><span
            class="n">suc</span><span class="p">:</span>
                <span class="n">where</span><span class="o">.</sp