Invoice total amount without Tax (ibt-109) = Σ Invoice line net amount (ibt-131) - Sum of allowances on document level (ibt-107) + Sum of charges on document level (ibt-108).
cac:LegalMonetaryTotal((cbc:ChargeTotalAmount) and (cbc:AllowanceTotalAmount) and (xs:decimal(cbc:TaxExclusiveAmount) = round((xs:decimal(cbc:LineExtensionAmount) + xs:decimal(cbc:ChargeTotalAmount) - xs:decimal(cbc:AllowanceTotalAmount)) * 10 * 10) div 100 )) or (not(cbc:ChargeTotalAmount) and (cbc:AllowanceTotalAmount) and (xs:decimal(cbc:TaxExclusiveAmount) = round((xs:decimal(cbc:LineExtensionAmount) - xs:decimal(cbc:AllowanceTotalAmount)) * 10 * 10 ) div 100)) or ((cbc:ChargeTotalAmount) and not(cbc:AllowanceTotalAmount) and (xs:decimal(cbc:TaxExclusiveAmount) = round((xs:decimal(cbc:LineExtensionAmount) + xs:decimal(cbc:ChargeTotalAmount)) * 10 * 10 ) div 100)) or (not(cbc:ChargeTotalAmount) and not(cbc:AllowanceTotalAmount) and (xs:decimal(cbc:TaxExclusiveAmount) = xs:decimal(cbc:LineExtensionAmount)))