ass1   = mark for assignment 1    (out of 8)
ass2   = mark for assignment 2    (out of 10)
ass3   = mark for assignment 3    (out of 12)
labs   = mark for assessed labs   (out of 10)
pexam  = mark for prac exam       (out of 30)
wexam  = mark for written exam    (out of 30)

okExam = (pexam >= 15/30) && (wexam >= 12/30)

mark   = ass1 + ass2 + ass3 + labs + pexam + wexam
grade  = HD|DN|CR|PS  if mark ≥ 50 && okExam
       = FL           if mark < 50 && okExam
       = UF           if !okExam