counter</span> <span class="mdzsyn-number">0</span>)

(<span class="mdzsyn-coresym">defn</span> <span class="mdzsyn-symbol">worker</span>
  <span class="mdzsyn-string">"A worker that is unreliable and sometimes fails."</span>
  []
  (<span class="mdzsyn-coresym">repeat</span> <span class="mdzsyn-number">50</span>
    (<span class="mdzsyn-coresym">print</span> <span class="mdzsyn-string">"working..."</span>)
    (<span class="mdzsyn-coresym">ev/sleep</span> <span class="mdzsyn-number">0.1</span>)
    (<span 