14-15 (OBJECTIVE 14-5) Explain what is meant by lapping and discuss how the auditor can uncover it. Under what circumstances should the auditor make a special effort to uncover lapping? 14-16 (OBJECTIVE 14-6) What audit procedures are most likely to be used to verify accounts receivable written off as uncollectible? State the purpose of each of these procedures. 14-17 (OBJECTIVES 14-3, 14-5) Under what circumstances is it acceptable to perform tests of controls and substantive tests of transactions for sales and cash receipts at an interim date