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

<start>
  <element name="test">
  <data type="token">
  <param name="pattern">[a-z]+</param>
  </data>
  </element>
</start>

</grammar>