<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

  <xsd:element name="A" type="X"/>

  <!-- The purpose of this element is:

       a) To have a fixed attribute use

       b) To have an attribute with a fixed attribute declaration

       c) To have a complex type with simple content and a fixed value

       d) To have an element declaration with a fixed value

   -->

  <xsd:element name="B" fixed="howdy">

    <xsd:complexType>

      <xsd:simpleContent>

        <xsd:extension base="xsd:string">

          <xsd:attribute ref="fixedAttr" use="required" fixed="hello"/>

        </xsd:extension>

      </xsd:simpleContent>

    </xsd:complexType>

  </xsd:element>

  <xsd:element name="D" type="xsd:string" fixed="hey"/>

  <xsd:attribute name="attr" type="xsd:string"/>

  <xsd:attribute name="unparsedEntityAttr" type="xsd:ENTITIES"/>

  <xsd:attribute name="fixedAttr" type="xsd:string" fixed="hello"/>

  <xsd:complexType name="X">

    <xsd:sequence>

      <xsd:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

    </xsd:sequence>

    <xsd:attribute ref="attr"/>

    <xsd:attribute ref="unparsedEntityAttr"/>

  </xsd:complexType>

  <xsd:complexType name="Y">

    <xsd:complexContent>

	    <xsd:restriction base="X">

		    <xsd:sequence>

		      <xsd:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

		    </xsd:sequence>

		    <xsd:attribute ref="attr" fixed="typeY"/>

		    <xsd:attribute ref="unparsedEntityAttr" use="prohibited"/>

	    </xsd:restriction>

    </xsd:complexContent>

  </xsd:complexType>

  <!-- Z is the same as X, but is not derived from X. -->

  <xsd:complexType name="Z">

    <xsd:sequence>

      <xsd:any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

    </xsd:sequence>

    <xsd:attribute ref="attr"/>

    <xsd:attribute ref="unparsedEntityAttr"/>

  </xsd:complexType>

  <xsd:complexType name="idType">

    <xsd:complexContent>

	    <xsd:extension base="X">

		    <xsd:attribute name="idAttr" type="xsd:ID"/>

	    </xsd:extension>

    </xsd:complexContent>

  </xsd:complexType>

  <xsd:complexType name="idrefType">

    <xsd:complexContent>

	    <xsd:extension base="X">

		    <xsd:attribute name="idrefAttr" type="xsd:IDREF"/>

	    </xsd:extension>

    </xsd:complexContent>

  </xsd:complexType>

</xsd:schema>