(define COURSES
'((cs101 cs102 Petty)
  (cs102 NONE Petty cs101 math101)
  (cs201 cs202 Vega (cs102 ee105) math101)
  (cs202 cs330 Gabriel cs201)
  (cs230 cs330 Vega cs201 math102)
  (cs330 NONE Vega (cs202 cs230) math102)
  (cs340 cs341 Gabriel cs202)
  (cs341 NONE Gabriel cs340)
  (cs380 NONE Gabriel cs102)
  (math102 NONE Lee math101))
)