<!-- file "http://example.com/abc/main.xsd" -->
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
	xmlns:abc="http://example.com/abc"
	targetNamespace="http://example.com/xyz">
	<xsd:include schemaLocation="http://example.com/abc/sub1.xsd"/>
	<xsd:import namespace="http://www.w3.org/2001/XMLSchema" 
	schemaLocation="http://example.com/xyz/schema.xsd"/>
	<xsd:redefine schemaLocation="http://example.com/abc/sub2.xsd">
	<xsd:attribute name="sub2-attr" type="xsd:token"/>
</xsd:redefine>
	<xsd:element name="abc-elem" type="Xyz-type"/>
</xsd:schema>