Represent, using the proper symbols, the following actions: [6 points]

a. An external entity Supplier sending an invoice to a process Deal with payment. Assume the process takes place in the Accounts division.

b. A process called Update membership writing customer details to a data store called Customers. Assume the process is performed by the Membership Secretary.

c. A process called Order raw materials is performed by the Purchasing Clerk. To do this the clerk retrieves details from the Supplier data store and sends the purchase order to the external entity Supplier. The clerk also stores the purchase order details in a data store Purchase orders.