<?xml version="1.0"?>

<rulebase
xmlns="http://www.ruleml.org/0.86/xsd"
xsi:schemaLocation="http://www.ruleml.org/0.86/xsd http://www.ruleml.org/0.86/xsd/hornlog.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>

<!-- non-ground-fact-like rule with 4-element plex as single argument -->

<fact>
  <_head>
    <atom>
      <_opr><rel>book</rel></_opr>
      <plex>
        <var>title</var>
        <var>autor</var>
        <var>toc</var>
        <var>chapters</var>
      </plex>
    </atom>
  </_head>
</fact>


</rulebase>

