<grammar xmlns=“relaxng.org/ns/structure/1.0” datatypeLibrary=“www.w3.org/2001/XMLSchema-datatypes”>

<define name="position">
  <element ns="http://cpee.org/ns/properties/2.0">
    <anyName/>
    <optional>
      <attribute name="passthrough">
        <data type="string"/>
      </attribute>
    </optional>
    <data type="string">
      <param name="pattern">(at|after)</param>
    </data>
  </element>
</define>

</grammar>