code> tests for structural equality of <code class="code">e1</code> and <code class="code">e2</code>.
   Mutable structures (e.g. references and arrays) are equal
   if and only if their current contents are structurally equal,
   even if the two mutable objects are not the same physical object.
   Equality between functional values raises <code class="code"><span class="constructor">Invalid_argument</span></code>.
   Equality between cyclic data structures may not terminate.<br>
</div>

<pre><span id="VAL(