Refer to the class notes and the University E/R diagram. 1. Write an assertion which limits the enrollment in computer science sections to 40 or less students. 2. Write an assertion for the rule: "A student may not enroll in more than 6 courses per year". 3. Suppose we want to ensure that the foreign key CourseId values of the SECTION table records are never modified, either accidentally or intentionally. That is, no section should possibly be assigned to a different course other than the course it was originally intended for. Design a trigger that intercepts a modification to this field and sets the value back to what it was. The University E/R diagram