Using ERDPlus, create an ERD that can be implemented for a medical clinic, using

the following business rules:

$1.$ A patient can make many appointments with one or more doctors in the clinic,

and a doctor can accept appointments with many patients. However, each

appointment is made with only one doctor and one patient.

$2.$ If kept, an appointment yields a visit with the doctor specified in the appointment. Some appointments get cancelled and do not yield visits. Some visits

are walk$-$in$,$ and are not linked to an appointment.

$3.$ For each visit, there could be one or many diagnoses and corresponding treatments for those diagnoses.

$4.$ Each visit creates a bill. Each bill is linked to just one visit.

$5.$ Each bill must be paid. However, a bill may be paid in many installments,

and a payment may cover more than one bill.