 <code>subst1</code> and <code>subst2</code>. The first component of the output is this common part. The second and third components are the remainder of <code>subst1</code> and <code>subst2</code>, respectively.</p></div></div><div class="odoc-spec"><div class="spec value" id="val-sub_symmetric_difference" class="anchored"><a href="#val-sub_symmetric_difference" class="anchor"></a><code><span><span class="keyword">val</span> sub_symmetric_difference : <span><a href="#type-subst">subst</a> <span class="arro