Professors work on $($research$)$ projects for the university. Professors have an $SSN,$ name, age, rank, and a research specialty. Projects have a project number, a sponsor name $($e$.$g$.,$ NSF$),$ and a budget. Each project must have only one professor that is the principal investigator or manager. Not all professors might be engaged on a research project at a given time, however, projects should have at least one professor assigned to work on them. The university encourages collaboration on projects among multiple professors working on them. Because projects are so time$-$consuming, most professors are working on more than one project. Professors might belong to one department, and departments will have one or more professors that belong to it$.$ A department number, department, name, and a main office characterize a department. One of the department professors will chair $($lead$)$ it$,$ and a department can have only one chair at a time.