{
  "resourceType": "StructureDefinition",
  "url": "https://fhir.nhs.uk.uk/StructureDefinition/NHSDigital-Range",
  "name": "NHSDigitalRange",
  "status": "draft",
  "fhirVersion": "4.0.1",
  "kind": "complex-type",
  "abstract": false,
  "type": "Range",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Range",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Range",
        "path": "Range",
        "constraint": [
          {
            "key": "nhsd-rng1",
            "severity": "error",
            "human": "If both low and high present, both should use the same units or both should have units absent",
            "expression": "low.empty() or high.empty() or (low.unit = high.unit) or (low.unit.empty() and high.unit.empty())",
            "source": "https://fhir.nhs.uk.uk/StructureDefinition/NHSDigital-Range"
          }
        ]
      },
      {
        "id": "Range.low.value",
        "path": "Range.low.value",
        "min": 1
      },
      {
        "id": "Range.high.value",
        "path": "Range.high.value",
        "min": 1
      }
    ]
  }
}