 <code class="type">('a -&gt; 'b -&gt; 'c -&gt; 'a) -&gt; 'a -&gt; 'b list -&gt; 'c list -&gt; 'a</code></pre><div class="info ">
<div class="info-desc">
<p><code class="code"><span class="constructor">List</span>.fold_left2&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></c