Message

TAX category tax amount = TAX category taxable amount x (TAX category rate / 100), rounded to two decimals.

Context
cac:TaxTotal/cac:TaxSubtotal
Test
(round(cac:TaxCategory/xs:decimal(cbc:Percent)) = 0 and (round(xs:decimal(cbc:TaxAmount)) = 0)) or (round(cac:TaxCategory/xs:decimal(cbc:Percent)) != 0 and (xs:decimal(cbc:TaxAmount) = round(xs:decimal(cbc:TaxableAmount) * (cac:TaxCategory/xs:decimal(cbc:Percent) div 100) * 10 * 10) div 100 )) or (not(exists(cac:TaxCategory/xs:decimal(cbc:Percent))) and (round(xs:decimal(cbc:TaxAmount)) = 0))