an>(<span class="type-var">'a</span>, <span>[ `Struct ]</span>)</span> <a href="#type-structured">structured</a></span></span></code></div></div><div class="odoc-spec"><div class="spec type anchored" id="type-union"><a href="#type-union" class="anchor"></a><code><span><span class="keyword">type</span> <span>!'a union</span></span><span> = <span><span>(<span class="type-var">'a</span>, <span>[ `Union ]</span>)</span> <a href="#type-structured">structured</a></span></span></code></div></div><div class="odoc-s