(define STUDENTS  
 '((jim ())
   (jane (mat101 csc108))
   (john (mat101 csc108 csc148 csc270))
   (emily (mat101 csc108 mat246))
   (emma (mat101 csc108 csc148 mat246))
  )
)

(define COURSES 
 '((csc108 ())
   (csc148 (csc108 mat101))
   (csc238 (csc148))
   (csc260 (csc108))
   (csc270 (csc148))
   (csc310 ((csc260 csc270) (sta107 sta205 sta255)))
   (csc324 (csc148 (csc238 mat246)))
  )
)