<?xml version="1.0" encoding="UTF-8"?>

<!--
  Variations/FRBR Project schema release 1.1
-->

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

            xmlns="http://vfrbr.info/vfrbr/1.1/structure"
            targetNamespace="http://vfrbr.info/vfrbr/1.1/structure"
            elementFormDefault="qualified"
            attributeFormDefault="unqualified"
            >

  <!--
    XML element definitions
    for the FRBR Structure relationshipTypes
    -->

  <xsd:element name="realizedThrough"
               type="RealizedThroughType"
               />
  <xsd:element name="embodiedIn"
               type="EmbodiedInType"
               />
  <xsd:element name="exemplifiedBy"
               type="ExemplifiedByType"/>

  <!--
    type for realizedThrough
    -->
  <xsd:complexType name="RealizedThroughType">

    <xsd:attribute name="sourceEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="work"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="sourceURI"
                   type="xsd:anyURI"
                   use="required"/>

    <xsd:attribute name="targetEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="expression"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="targetURI"
                   type="xsd:anyURI"
                   use="required"/>

  </xsd:complexType>

  <!--
    type for embodiedIn
    -->
  <xsd:complexType name="EmbodiedInType">

    <xsd:attribute name="sourceEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="expression"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="sourceURI"
                   type="xsd:anyURI"
                   use="required"/>

    <xsd:attribute name="targetEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="manifestation"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="targetURI"
                   type="xsd:anyURI"
                   use="required"/>

  </xsd:complexType>

  <!--
    type for exemplifiedBy
    -->
  <xsd:complexType name="ExemplifiedByType">

    <xsd:attribute name="sourceEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="manifestation"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="sourceURI"
                   type="xsd:anyURI"
                   use="required"/>

    <xsd:attribute name="targetEntity"
                   use="required">
      <xsd:simpleType>
        <xsd:restriction base="xsd:string">
          <xsd:enumeration value="item"/>
        </xsd:restriction>
      </xsd:simpleType>
    </xsd:attribute>

    <xsd:attribute name="targetURI"
                   type="xsd:anyURI"
                   use="required"/>

  </xsd:complexType>

</xsd:schema>

