Given the following narrative, do the following:
a. Develop an activity diagram for each scenario, and
b. Complete a fully developed use case description for each scenario.

Quality Building Supply has two kinds of customers: contractors and the general public. Sales to each are slightly different.
A contractor buys materials by taking them to the contractor’s checkout desk. The clerk enters the contractor’s name into the system. The system displays the contractor’s information, including current credit standing.
The clerk then opens up a new ticket (sale) for the contractor. Next, the clerk scans in each item to be purchased. The system finds the price of the item and adds the item to the ticket. At the end of the purchase, the clerk indicates the end of the sale. The system compares the total amount against the contractor’s current credit limit and, if it is acceptable, finalizes the sale. The system creates an electronic ticket for the items, and the contractor’s credit limit is reduced by the amount of the sale. Some contractors like to keep a record of their purchases, so they request that the ticket details be printed. Others aren’t interested in a printout.
A sale to the general public is simply entered into the cash register, and a paper ticket is printed as the items are identified. Payment can be by cash, check, or credit card. The clerk must enter the type of payment to ensure that the cash register balances at the end of the shift. For credit-card payments, the system prints a credit-card voucher that the customer must sign.