+++
+++

<https://github.com/w3c/activitystreams/issues/542>

as:closed is defined as Object | Link | xsd:boolean | xsd:datetime

the normative context explicitly types the value to a datetime

solution: define `closedBy` as a term definition for as:closed but with `@type: @id`

```json
  "as": "https://www.w3.org/ns/activitystreams#",
  // ...
  "closedBy": {
    "@id": "as:closed",
	 "@type": "@id"
  },
  // ...
```