(a) All entities with their attributes must be represented, indicating all candidate keys. You must indicate and justify all assumptions you have made.

(b) Describe non-trivial domains for attributes where needed.

(c) Make a decision about the cardinality and participation constraints of all relationships, and add appropriate symbols to the

A database is needed to keep track of the operations of a physical therapy center. Every patient must be referred by a physician and have a prescription for physical therapy in order to receive treatments. A patient may have different physicians at different times. The database keeps all information about prescriptions and treatments, both past and current. When appointments are made, the information about scheduled date and time is recorded. No patient is ever scheduled for two visits on one day. The center has several physical therapists, and a patient may be treated by different physical therapists on different visits. When a patient makes a visit at an appointed time, the name of the therapist, the treatment, the date, the time, and the equipment used are all recorded for that visit. Each of these has only one value for the visit. This information will be used later for insurance billing, which is not part of this database. Draw a complete E-R diagram for this example