@Q:
RETURN POSITION( [<span class="hljs-number">2</span>,<span class="hljs-number">4</span>,<span class="hljs-number">6</span>,<span class="hljs-number">8</span>], <span class="hljs-number">4</span>, <span class="hljs-literal">true</span> )

@R
[
  <span class="hljs-number">1</span>
]