Invoice total VAT amount (BT-110) = Σ VAT category tax amount (BT-117).
/ubl:Invoice/cac:TaxTotal | /cn:CreditNote/cac:TaxTotal(xs:decimal(child::cbc:TaxAmount)= round((sum(cac:TaxSubtotal/xs:decimal(cbc:TaxAmount)) * 10 * 10)) div 100) or not(cac:TaxSubtotal)