use balanced sums for constructors (to gracefully handle 100 constructors or more)
<?xml version="1.0"?>
<locatingRules xmlns="http://thaiopensource.com/ns/locating-rules/1.0">
<uri resource="pgip_isar.xml" uri="pgip.rnc"/>
<uri resource="pgip_isar.xml" typeId="RELAX NG"/>
</locatingRules>