Ansible: when list in list
<p>I have two lists:</p>

<pre><code>a:
 - 1
 - 2 
 - 3
b: 
 - 2
 - 3
 - 4
</code></pre>

<p>I need to run a task only when any of items in <code>a</code> is contained in <code>b</code>. How is this possible?</p>

<pre><code>tasks:
  - name: one of elements of a in b
    debug: msg=At least one of elements of a is contained in b
    when: ???
</code></pre>