<simple_comment_introducer xmlns="http://www.sqlparser.com/xml/ansi2003"> <minus_sign>{2,2}</minus_sign> </simple_comment_introducer>
<xs:element name="simple_comment_introducer"> <xs:complexType> <xs:sequence> <xs:element ref="minus_sign" maxOccurs="2" minOccurs="2"/> </xs:sequence> </xs:complexType> </xs:element>