<xs:complexType name="Thing">
<xs:complexContent>
<xs:extension base="ax:Object">
<xs:sequence>
<xs:element maxOccurs="unbounded" minOccurs="0" name="Thing" nillable="true" type="ax:Item"/>
<xs:element minOccurs="0" name="number" nillable="true" type="xs:double"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
This is the XSD structure