&gt; 'b) -&gt; 'a list -&gt; 'b -&gt; 'b</pre><div class="info ">
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<p><code class="code">fold_right&nbsp;f&nbsp;[a1;&nbsp;...;&nbsp;an]&nbsp;init</code> is
   <code class="code">f&nbsp;a1&nbsp;(f&nbsp;a2&nbsp;(...&nbsp;(f&nbsp;an&nbsp;init)&nbsp;...))</code>. Not tail-recursive.</p>
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<h2 id="1_Iteratorsontwolists">Iterators on two lists</h2>
<pre id="VALiter2">val iter2 : ('a -&gt; 'b -&gt; unit) -&gt; 'a list -&gt; 'b list -&gt; unit</pre><div class="info ">
<div class="