<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:other_ns="http://other_ns"
           targetNamespace="http://other_ns"
           elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:element name="abstractElt" abstract="true"/>
<xs:element name="realizationOfAbstractElt" substitutionGroup="other_ns:abstractElt">
  <xs:complexType>
    <xs:sequence>
        <xs:element name="foo" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>
