libopc/third_party/libxml2-2.7.7/test/relaxng/tutor5_2.rng

<element name="point" xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <element name="x">
    <data type="double"/>
  </element>
  <element name="y">
    <data type="double"/>
  </element>
</element>