| 摘要 |
PROBLEM TO BE SOLVED: To suppress unauthorized use of a certificate of payment certifying that payment has been made for merchandise.SOLUTION: A merchandise sales data processor, while performing merchandise sales registration relevant to one transaction and issuing a receipt, issues a certificate of payment 50 indicating transaction information relevant to the one transaction and certifying that payment has been made for merchandise. Thereby, based on the transaction information indicated on the certificate of payment 50, it is easily determined whether the certificate of payment 50 is the one illicitly reused. |
