1<xs:schema xmlns:tns="http://myns" 2 targetNamespace="http://myns" 3 xmlns:xs="http://www.w3.org/2001/XMLSchema" 4> 5 6 <xs:element name="a" /> 7 8 <xs:complexType name="c" > 9 <xs:sequence minOccurs="2" maxOccurs="4"> 10 <xs:sequence minOccurs="19" maxOccurs="20"> 11 <xs:element ref="tns:a" /> 12 </xs:sequence> 13 </xs:sequence> 14 </xs:complexType> 15 16 <xs:element name="c" type="tns:c" /> 17 18</xs:schema> 19