| <?xml version="1.0"?> | |
| <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> | |
| <xs:element name="doc"> | |
| <xs:complexType> | |
| <xs:sequence> | |
| <xs:choice minOccurs="0" maxOccurs="1"> | |
| <xs:element name="a"/> | |
| <xs:element name="b"/> | |
| </xs:choice> | |
| </xs:sequence> | |
| </xs:complexType> | |
| </xs:element> | |
| </xs:schema> |