square(L):-
	    L=[X1,X2,X3,X4,X5,X6,X7,X8,X9],
        fd_domain(L,1,9),
        fd_all_different(L),
        X1+X2+X3#=15,
        X4+X5+X6#=15,
        X7+X8+X9#=15,
        X1+X4+X7#=15,
        X2+X5+X8#=15,
        X3+X6+X9#=15,
        X3+X5+X7#=15,
        X1+X5+X9#=15,
        fd_labeling(L).