End date of line period MUST be within invoice period.
PEPPOL-EN16931-R111pxs-taxdata:TaxData/pxs-taxdata:ReportedTransaction/pxs-taxdata:ReportedDocument[cac:InvoicePeriod/cbc:EndDate]/pxs-taxdata:DocumentLine/cac:InvoicePeriod/cbc:EndDatexs:date(text()) <= xs:date(../../../cac:InvoicePeriod/cbc:EndDate)