<xs:complexType name="CT_Operator" xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:element name="state" type="CT_State" /> <xs:element name="and" type="CT_Operator" /> <xs:element name="or" type="CT_Operator" /> <xs:element name="not" type="CT_Operator" /> </xs:choice> </xs:complexType>