<!DOCTYPE html>
<link rel="stylesheet" href="test-common.css">
<style type="text/css">
  @counter-style a {
    system: extends upper-roman;
    range: infinite -3, -1 2, 4 4, 7 9, 11 infinite;
  }
</style>
<ol start="-3" style="list-style-type: a">
  <li><li><li><li><li>
  <li><li><li><li><li>
  <li><li><li><li><li>
  <li value="3999"><li>
</ol>