Marking scheme for A2

Correctness: 15 marks
   took                 ... / 2 marks
   is_prereq            ... / 3 marks
   can_take             ... / 3 marks
   can_take_list        ... / 2 marks
   all_students         ... / 2 marks
   all_courses_taken    ... / 3 marks

Comments        ... / 2 marks

Testing         ... / 3 marks 
 (queries and answers for each predicate, 0.5 marks each)


Total:  ... /  Out of 20 marks