/db/projects/hirt/web/briefe/detail.xqlexerr:ERROR XPTY0004: The actual cardinality for parameter 1 does not match the cardinality declared in the function's signature: concat($atomizable-values as xs:anyAtomicType?, ...) xs:string. Expected cardinality: zero or one, got 2. [at line 148, column 42, source: /db/projects/hirt/web/briefe/detail.xql]