NOTE: This question was previously posted, but the answer given was a generic non-answer that did not pertain in ANY way to the specifics of what was being asked. Do NOT put generic ERD information as an answer, as it will NOT be accepted.

A new database system will be created to consolidate what are currently three separate systems.

The resulting new system will support the following enterprise description: Professors and GTAs are assigned to teach the sections of each class being offered in a semester.

At the end of the semester, they get a "team rating" (professors and GTAs together get one rating per section and the rating is not done on an individual).

To support the assignment of professors to sections, a record is kept of which class each professor can teach. Classes can have one or more prerequisite classes. Students can take several sections each semester, and receive a grade for taking each section.

Students may end up waiting for some sections, and receive a "rank" (determining the order they will be admitted if other students drop). However, no more than 10 students can wait on a class at the same time. Note that GTAs are students, however they differ in that they have a salary. All people (e.g. students, professors) are uniquely identified by their social security number.

All classes are identified by department name (e.g. "INFS") and course number (e.g. "614"). Sections of classes are distinguished by their section number (e.g. "02").

Given the above requirements:

1. Draw an ERD for the database, identifying:

(i) all the entity sets;

(ii) all the relationship sets and their multiplicity;

(iii) the primary key for each entity set (and weak entity set, if any) and each relationship set.

You may invent additional attributes for entity sets.

2. Indicate features and properties from the requirements description that are not captured by the ERD from (1).