ta_assignment says which teaching assistant (TA) helps each student in each course. The rules:

(student, course) → ta     each student has one TA per course
ta → course                each TA works for one course

1. Test ta → course on the data: return each ta and the number of different courses.
2. Is ta a superkey of ta_assignment?
3. (student, course) is a candidate key. Which two attributes form the other one?
4. Split on ta → course. Create ta_course(ta, course) with key ta.
5. Create student_ta(student, ta) with key (student, ta) and a foreign key to ta_course.
6. Join the two new tables. Return student, course, ta. The rows must be the same as in ta_assignment.
7. Which FD can no key of the new tables enforce?