 class="n">first</span> <span class="o">=</span> <span
            class="n">first</span>
        <span class="n">first</span><span class="o">.</span><span class="n">pred</span> <span class="o">=</span> <span
            class="n">where</span>
        <span class="n">T_left</span><span class="o">.</span><span class="n">last</span> <span class="o">=</span> <span
            class="n">where</span>
        <span class="n">where</span><span class="o">.</span><span class="n">suc</span> <span class="o">=</span> <