Message

When Supplier is Greek, the Invoice Id in the fourth segment must be a valid greek document type

Context
/ubl-invoice:Invoice/cbc:ID[$isGreekSender] | /ubl-creditnote:CreditNote/cbc:ID[$isGreekSender]
Test
string-length(normalize-space($IdSegments[4]))>0 and (some $c in $greekDocumentType satisfies $IdSegments[4] = $c)