<StructureDefinition xmlns="http://hl7.org/fhir">
  <url value="https://example.org/fhir/StructureDefinition/MyPatient" />
  <name value="MyPatient" />
  <status value="draft" />
  <fhirVersion value="4.0.1" />
  <kind value="resource" />
  <abstract value="false" />
  <type value="Patient" />
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Patient" />
  <derivation value="constraint" />
  <differential>
    <element id="Patient.address">
      <path value="Patient.address" />
      <short value="An address expressed using postal conventions (as opposed to GPS or other location definition formats)" />
      <definition value="An address expressed using postal conventions (as opposed to GPS or other location definition formats).  This data type may be used to convey addresses for use in delivering mail as well as for visiting locations which might not be valid for mail delivery.  There are a variety of postal address formats defined around the world." />
      <comment value="Note: address is intended to describe postal addresses for administrative purposes, not to describe absolute geographical coordinates.  Postal addresses are often used as proxies for physical locations (also see the [Location](location.html#) resource)." />
      <type>
        <code value="Address" />
        <profile value="https://example.org/fhir/StructureDefinition/MyAddress" />
      </type>
      <constraint>
        <key value="ele-1" />
        <severity value="error" />
        <human value="All FHIR elements must have a @value or children" />
        <expression value="hasValue() or (children().count() &gt; id.count())" />
        <xpath value="@value|f:*|h:div" />
        <source value="http://hl7.org/fhir/StructureDefinition/Element" />
      </constraint>
      <constraint>
        <key value="Demo-1" />
        <requirements value="Something" />
        <severity value="error" />
        <human value="Example Error message" />
        <expression value="line.empty() or $this.hasValue()" />
        <source value="https://example.org/fhir/StructureDefinition/MyAddress" />
      </constraint>
    </element>
  </differential>
</StructureDefinition>