Student(sID, surName, firstName, campus, email, gpa)
Course(dept, cNum, name, breadth)
Offering(oID, dept, cNum, term, instructor)
Took(sID, oID, grade)
Offering[dept, cNum] ⊂ Course[dept, cNum]
Took[sID] ⊂ Student[sID]
Took[oID] ⊂ Offering[oID]
Q1. Courses at the 400-level cannot count for breadth
$\Pi_{dept, cNum} (\sigma_{cNum>400, breadth = True} \text{Course}) = \empty$
Q2. CSC490 can only be offered at the same time as CSC454
$\Pi_{term} (\sigma_{dept="CSC"\land cNum=490} \text{Offering}) \sub \Pi_{term} (\sigma_{dept="CSC"\land cNum=454} \text{Offering})$