If "Payment means type code" (BT-81) contains a code for direct debit (59), BG-17 and BG-18 shall not be provided.
(/ubl-invoice:Invoice/cac:PaymentMeans[cbc:PaymentMeansCode = 59] | /ubl-creditnote:CreditNote/cac:PaymentMeans[cbc:PaymentMeansCode = 59])[$supplierCountryIsDE and $customerCountryIsDE]not(cac:PayeeFinancialAccount) and not(cac:CardAccount)