subjects('1 Sep', 1, 2, 3).
subjects('2 Sep', 2, 3, 4).
subjects('3 Sep', 1, 2, 3).
subjects('4 Sep', 3, 5, 6).
subjects('5 Sep', 4, 5, 6).
subjects('6 Sep', 1, 2, 5).
subjects('8 Sep', 5, 6, 7).
subjects('9 Sep', 4, 5, 7).
subjects('10 Sep', 2, 4, 5).
subjects('11 Sep', 2, 4, 5).
subjects('12 Sep', 2, 3, 4).
subjects('14 Sep', 1, 2, 3).
subjects('15 Sep', 2, 3, 4).
subjects('16 Sep', 3, 5, 6).

printing:- subjects(X,Y,Z,W),write(' '),write(X),write(', '),write(Y),write(' '),write(Z),write(' '),write(W),nl,fail.
one_attr(Z):- subjects(X,Y,Z,W),write(' '),write(X),write(', '),write(Y),write(' '),write(Z),write(' '),write(W),nl,fail.
two_attr(Y, Z):-subjects(X,Y,Z,W),write(' '),write(X),write(', '),write(Y),write(' '),write(Z),write(' '),write(W),nl,fail.
sec_attr(X, Z):-subjects(X,Y,Z,W),write(' '),write(X),write(', '),write(Y),write(' '),write(Z),write(' '),write(W),nl,fail.