|''given rentals''|Joanna|
|''rental item''|''count''|''start date''|''end date''|
|cup|100|2004/05/05 09:01|2004/05/06 09:01|

|''begin transaction for client''| Joanna |''staff''| Bill|
|''return items''|100||cup|
|''refund cash $''|10.00|
|''complete transaction''|

|''rentals of client''|Joanna|
|''rental item''|

|''rental item subset''|
|''name''|''free count''|
|cup|500|
