<?xml version="1.0" encoding="UTF-8"?>
<grammar
xmlns="http://relaxng.org/ns/structure/1.0"
xmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0"
datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
<define name="pattern1">
<data type="string">
<param name="pattern">-?([0-9]+(\.[0-9]*)?|\.[0-9]+)</param>
</data>
</define>
<start>
<element name="elem1">
<attribute name="attr1">
<list>
<ref name="pattern1"/>
</list>
</attribute>
</element>
</start>
</grammar>