{
  "version": 1,
  "name": "Subtyping",
  "objectTypes": [
    {
      "id": "person",
      "name": "Person",
      "kind": "entity",
      "refMode": "nr"
    },
    {
      "id": "student",
      "name": "Student",
      "kind": "entity"
    },
    {
      "id": "subject",
      "name": "Subject",
      "kind": "entity",
      "refMode": "code"
    }
  ],
  "factTypes": [
    {
      "id": "enrolled",
      "roles": [
        {
          "id": "enrolled.r0",
          "objectTypeId": "student"
        },
        {
          "id": "enrolled.r1",
          "objectTypeId": "subject"
        }
      ],
      "readings": [
        {
          "id": "enrolled.rd",
          "roleOrder": [
            "enrolled.r0",
            "enrolled.r1"
          ],
          "text": "{0} is enrolled in {1}",
          "isPrimary": true
        }
      ]
    }
  ],
  "subtypeRelations": [
    {
      "id": "st",
      "subtypeId": "student",
      "supertypeId": "person",
      "isPreferredIdentificationPath": true
    }
  ],
  "constraints": [
    {
      "id": "uc",
      "kind": "uniqueness",
      "roles": [
        "enrolled.r0",
        "enrolled.r1"
      ]
    }
  ],
  "diagram": {
    "shapes": {
      "person": {
        "x": 60,
        "y": 30
      },
      "student": {
        "x": 60,
        "y": 170
      },
      "subject": {
        "x": 330,
        "y": 170
      },
      "enrolled": {
        "x": 220,
        "y": 178,
        "orientation": "horizontal"
      }
    }
  }
}