<!DOCTYPE html>
<link rel="stylesheet" href="test-common.css">
<style type="text/css">
@counter-style a {
system: extends decimal;
negative: '!';
negative: 0;
negative: ~;
negative: '(' 'x' ')';
}
</style>
<ol start="-2" style="list-style-type: a">
<li><li><li><li><li>
</ol>