<multiple_group_specification xmlns="http://www.sqlparser.com/xml/ansi2003"> <group_specification>{1,unbounded}</group_specification> </multiple_group_specification>
<xs:element name="multiple_group_specification"> <xs:complexType> <xs:sequence> <xs:element ref="group_specification" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> </xs:element>