student(s1, simon, 21, falmouth). student(s2, sally, 19, bristol). student(s3, john, 20, london). student(s4, wendy, 20, london). course(c1, nlp, peter). course(c2, image_proc, ela). course(c3, artificial_intell, bob). mark(s1, c1, 67.0). mark(s1, c3, 59.0). mark(s2, c1, 52.0). mark(s2, c3, 49.0). mark(s3, c2, 56.0). mark(s3, c3, 54.0). mark(s4, c1, 68.0). mark(s4, c3, 60.0).