Chained document queries — the client half of the provable semi-join:
SELECT * FROM <outer> WHERE $id IN (SELECT <join_property> FROM <inner> WHERE …).
FromProof + Fetch for [DocumentHavingEntries] — the
having-range (GROUP BY … HAVING <aggregate> <op> <value> LIMIT n) view of the unified getDocuments endpoint.
FromProof + Fetch for [DocumentRankedEntries] — the
ranked (GROUP BY … ORDER BY <aggregate> LIMIT n [OFFSET m])
view of the unified getDocuments endpoint.