Consider the following environment of a university. There are academic departments. Each department has a chairperson. Each department offers a set of courses. Some courses are currently offered. Some courses need prerequisites. An offering of a course is called a class or class section. A class is taught by a professor. It meets at a particular location. A course may have several sections with different meeting times. Some classes are scheduled in computer lab rooms. University staff are in charge of lab management. Not all departments offer the summer courses. Each faculty member is assigned to a single department and has a rank. Each student has an academic status $($undergraduate$,$ graduate, non$-$degree$).$ Each student is currently enrolled in a number of classes. Undergraduate students are allowed to have double majors. Some students are performing better because they are hard working. Students' financial aids depend on their academic performance measured by GPA. Graduate students can have individual faculty as their advisor in writing research thesis. Students may join various campus organizations $($clubs or societies$)$ to enrich their academic experiences and campus life. Each organization has a name, email, etc listed at the organization$$s website.