{
  "resourceType": "StructureDefinition",
  "url": "https://example.org/fhir/StructureDefinition/Model",
  "name": "Model",
  "status": "draft",
  "fhirVersion": "4.0.1",
  "kind": "logical",
  "abstract": false,
  "type": "https://example.org/fhir/StructureDefinition/Model",
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Element",
  "derivation": "specialization",
  "snapshot": {
    "element": [
      {
        "id": "Model",
        "path": "Model",
        "short": "Base for all elements",
        "definition": "Base definition for all elements in a resource.",
        "min": 0,
        "max": "*",
        "base": {
          "path": "Model",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Element"
          }
        ],
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Model.id",
        "path": "Model.id",
        "representation": [
          "xmlAttr"
        ],
        "short": "Unique id for inter-element referencing",
        "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Element.id",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "extension": [
              {
                "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
                "valueUrl": "string"
              }
            ],
            "code": "http://hl7.org/fhirpath/System.String"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          }
        ]
      },
      {
        "id": "Model.extension",
        "path": "Model.extension",
        "slicing": {
          "discriminator": [
            {
              "type": "value",
              "path": "url"
            }
          ],
          "description": "Extensions are always sliced by (at least) url",
          "rules": "open"
        },
        "short": "Additional content defined by implementations",
        "definition": "May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.",
        "comment": "There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.",
        "alias": [
          "extensions",
          "user content"
        ],
        "min": 0,
        "max": "*",
        "base": {
          "path": "Element.extension",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Extension"
          }
        ],
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ext-1",
            "severity": "error",
            "human": "Must have either extensions or value[x], not both",
            "expression": "extension.exists() != value.exists()",
            "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])",
            "source": "http://hl7.org/fhir/StructureDefinition/Extension"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          },
          {
            "identity": "rim",
            "map": "N/A"
          }
        ]
      },
      {
        "id": "Model.List",
        "extension": [
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
            "valueCode": "normative"
          },
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version",
            "valueCode": "4.0.0"
          }
        ],
        "path": "Model.List",
        "short": "A reference from one resource to another",
        "definition": "A reference from one resource to another.",
        "comment": "References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.",
        "min": 0,
        "max": "1",
        "base": {
          "path": "Model.List",
          "min": 0,
          "max": "1"
        },
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/List"
            ]
          }
        ],
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ref-1",
            "severity": "error",
            "human": "SHALL have a contained resource if a local reference is provided",
            "expression": "reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))",
            "xpath": "not(starts-with(f:reference/@value, '#')) or exists(ancestor::*[self::f:entry or self::f:parameter]/f:resource/f:*/f:contained/f:*[f:id/@value=substring-after(current()/f:reference/@value, '#')]|/*/f:contained/f:*[f:id/@value=substring-after(current()/f:reference/@value, '#')])",
            "source": "http://hl7.org/fhir/StructureDefinition/Reference"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          },
          {
            "identity": "rim",
            "map": "The target of a resource reference is a RIM entry point (Act, Role, or Entity)"
          }
        ]
      },
      {
        "id": "Model.patient",
        "extension": [
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
            "valueCode": "normative"
          },
          {
            "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version",
            "valueCode": "4.0.0"
          }
        ],
        "path": "Model.patient",
        "short": "A reference from one resource to another",
        "definition": "A reference from one resource to another.",
        "comment": "References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.",
        "min": 0,
        "max": "*",
        "base": {
          "path": "Model.patient",
          "min": 0,
          "max": "*"
        },
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/Patient"
            ]
          }
        ],
        "condition": [
          "ele-1"
        ],
        "constraint": [
          {
            "key": "ele-1",
            "severity": "error",
            "human": "All FHIR elements must have a @value or children",
            "expression": "hasValue() or (children().count() > id.count())",
            "xpath": "@value|f:*|h:div",
            "source": "http://hl7.org/fhir/StructureDefinition/Element"
          },
          {
            "key": "ref-1",
            "severity": "error",
            "human": "SHALL have a contained resource if a local reference is provided",
            "expression": "reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))",
            "xpath": "not(starts-with(f:reference/@value, '#')) or exists(ancestor::*[self::f:entry or self::f:parameter]/f:resource/f:*/f:contained/f:*[f:id/@value=substring-after(current()/f:reference/@value, '#')]|/*/f:contained/f:*[f:id/@value=substring-after(current()/f:reference/@value, '#')])",
            "source": "http://hl7.org/fhir/StructureDefinition/Reference"
          }
        ],
        "mapping": [
          {
            "identity": "rim",
            "map": "n/a"
          },
          {
            "identity": "rim",
            "map": "The target of a resource reference is a RIM entry point (Act, Role, or Entity)"
          }
        ]
      }
    ]
  },
  "differential": {
    "element": [
      {
        "id": "Model",
        "path": "Model",
        "min": 0,
        "max": "*",
        "type": [
          {
            "code": "Element"
          }
        ]
      },
      {
        "id": "Model.List",
        "path": "Model.List",
        "min": 0,
        "max": "1",
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/List"
            ]
          }
        ]
      },
      {
        "id": "Model.patient",
        "path": "Model.patient",
        "min": 0,
        "max": "*",
        "type": [
          {
            "code": "Reference",
            "targetProfile": [
              "http://hl7.org/fhir/StructureDefinition/Patient"
            ]
          }
        ]
      }
    ]
  }
}