nbsp;f&nbsp;a&nbsp;[b1;&nbsp;...;&nbsp;bn]&nbsp;[c1;&nbsp;...;&nbsp;cn]</code> is
   <code class="code">f&nbsp;(...&nbsp;(f&nbsp;(f&nbsp;a&nbsp;b1&nbsp;c1)&nbsp;b2&nbsp;c2)&nbsp;...)&nbsp;bn&nbsp;cn</code>.
   Raise <code class="code"><span class="constructor">Invalid_argument</span></code> if the two lists are determined
   to have different lengths.</p>
</div>
</div>

<pre><span id="VALfold_right2"><span class="keyword">val</span> fold_right2</span> : <code class="type">f:('a -&gt; 'b -&gt; 'c -&gt; 'c) -