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