Consider the following schema.
Student(Ssn, Name)
TakenCourses(Ssn, CourseNo)
Register(Ssn, CourseNo)
Course(CourseNo, Name, Year, Term)
PreRequisite(CourseNo, ReqCourseNo)
Table TakenCourses manages courses info that a student has taken. A course may require pre-requisite courses and the pre-requisite course info is managed in table PreRequisite. draw an ER diagram for this situation