nominal schema_v5 = ()
nominal operator = ()
nominal auditor = ()

union capability role =
    | OperatorCapability :: capability operator
    | AuditorCapability :: capability auditor

union document schema =
    | V5Document :: string -> document schema_v5

union query role schema result =
    | DigestQuery :: query auditor schema_v5 string

inl run_query forall role schema result.
    (capability : capability role)
    (query : query role schema result)
    (document : document schema)
    : result =
    match capability, query, document with
    | AuditorCapability, DigestQuery, V5Document digest => digest

inl main () : string =
    run_query OperatorCapability DigestQuery (V5Document "sha256")