<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="valueset-expression" />
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="vocab" />
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1" />
  </extension>
  <url value="http://hl7.org/fhir/StructureDefinition/valueset-expression" />
  <version value="4.0.0" />
  <name value="expression" />
  <status value="draft" />
  <date value="2018-12-27T22:37:54+11:00" />
  <publisher value="HL7" />
  <description value="An expression that provides an alternative definition of the content of the value set. There are two different ways to use this expression extension: If both an expression and a compose element is present, the compose is understood the make the same statement as the expression. If there is no compose, the expression is the only definition of the value set, and the value set can only be processed by a server that understands the expression syntax, it that is computable." />
  <fhirVersion value="4.0.0" />
  <mapping>
    <identity value="rim" />
    <uri value="http://hl7.org/v3" />
    <name value="RIM Mapping" />
  </mapping>
  <kind value="complex-type" />
  <abstract value="false" />
  <context>
    <type value="element" />
    <expression value="ValueSet" />
  </context>
  <type value="Extension" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" />
  <derivation value="constraint" />
  <differential>
    <element id="Extension">
      <path value="Extension" />
      <short value="An alternative computable expression of the value set content" />
      <definition value="An expression that provides an alternative definition of the content of the value set. There are two different ways to use this expression extension: If both an expression and a compose element is present, the compose is understood the make the same statement as the expression. If there is no compose, the expression is the only definition of the value set, and the value set can only be processed by a server that understands the expression syntax, it that is computable." />
      <comment value="The expression may be a reference or the actual expression, and ss expected to be a computable format (use the [rules-text extension](extension-valueset-rules-text.html) for a non-computable description)." />
      <min value="0" />
      <max value="1" />
    </element>
    <element id="Extension.extension">
      <path value="Extension.extension" />
      <max value="0" />
    </element>
    <element id="Extension.url">
      <path value="Extension.url" />
      <type>
        <code value="uri" />
      </type>
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/valueset-expression" />
    </element>
    <element id="Extension.valueExpression">
      <path value="Extension.valueExpression" />
      <type>
        <code value="Expression" />
      </type>
    </element>
  </differential>
</StructureDefinition>