de>. That is,
    <code class="code">assoc&nbsp;a&nbsp;[&nbsp;...;&nbsp;(a,b);&nbsp;...]&nbsp;=&nbsp;b</code>
    if <code class="code">(a,b)</code> is the leftmost binding of <code class="code">a</code> in list <code class="code">l</code>.
    Returns <code class="code"><span class="constructor">None</span></code> if there is no value associated with <code class="code">a</code> in the
    list <code class="code">l</code>.</p>
</div>
<ul class="info-attributes">
<li><b>Since</b> 4.05</li>
</ul>
</div>

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