The VAT category tax amount (BT-117) in a VAT breakdown (BG-23) where the VAT category code (BT-118) is "Export outside the EU" shall be 0 (zero).
/*/cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory[normalize-space(cbc:ID) = 'G'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']xs:decimal(../cbc:TaxAmount) = 0