l : ('a -&gt; 'a -&gt; bool) -&gt; 'a list -&gt; 'a list -&gt; bool</pre><div class="info ">
<div class="info-desc">
<p><code class="code">equal&nbsp;eq&nbsp;[a1;&nbsp;...;&nbsp;an]&nbsp;[b1;&nbsp;..;&nbsp;bm]</code> holds when
    the two input lists have the same length, and for each
    pair of elements <code class="code">ai</code>, <code class="code">bi</code> at the same position we have
    <code class="code">eq&nbsp;ai&nbsp;bi</code>.</p>

<p>Note: the <code class="code">eq</code> function may be cal