A JSON-LD Context for the query. In an API, this will frequently be implicit. For example, using json-rql as the body of a POST to http://example.com/my-api/v1/person/query might have the implicit context of a Person (possibly found at http://example.com/my-api/v1/person).

Specifies a Variable Expression or array of Variable Expressions that define [inline allowable value combinations]. This is a short-hand for including values in Groups in the @where clause.

specifies a pattern to match, or an array of patterns to match. Each can be a Subject, a Group, or another Query (a sub-query).