><span class="annot"
      ><span class="annottext"
	>[a] -&gt; [a] -&gt; [a]
forall a. [a] -&gt; [a] -&gt; [a]
</span
	><span class="hs-operator hs-var"
	>(++)</span
	></span
      ><span
      >
</span
      ><span id="line-30"
      ></span
      ><span
      >
</span
      ><span id="line-31"
      ></span
      ><span
      >
</span
      ><span id="line-32"
      ></span
      ><span class="hs-keyword"
      >class</span
      ><span
      > </span
      ><span id="Plugh"
      ><span class="annot"
	>