tests/org.eclipse.emf.test.xml/data/xml/x.xsd

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema 
    xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
    xmlns:ecore="http://www.eclipse.org/emf/2002/Ecore" 
    xmlns:x="http://www.example.com/X" 
    ecore:documentRoot="XDocumentRoot" 
    ecore:nsPrefix="x" 
    ecore:package="com.example.x" 
    ecore:ignoreSubstitutionGroups="true"
    targetNamespace="http://www.example.com/X">

  <xsd:element name="root" type="x:Root"/>
  <xsd:complexType name="Root">
    <xsd:sequence>
      <xsd:element maxOccurs="unbounded" ref="x:base"/>
      <xsd:element maxOccurs="unbounded" ref="x:value"/>
    </xsd:sequence>
  </xsd:complexType>

  <xsd:element name="value"/>
  <xsd:element name="intValue" type="xsd:int" substitutionGroup="x:value"/>
  <xsd:element name="floatValue" type="xsd:float" substitutionGroup="x:value"/>

  <xsd:element name="base" type="x:Base" abstract="true"/>
  <xsd:complexType name="Base" abstract="true"/>

  <xsd:element name="x" substitutionGroup="x:base" type="x:X"/>
  <xsd:complexType name="X">
    <xsd:complexContent>
      <xsd:extension base="x:Base">
        <xsd:sequence>
          <xsd:element name="a" type="xsd:string"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>
</xsd:schema>