The baby sits on the sandy beach.
There are no humans on the beach.
The baby cannot be on the beach if there are no humans there.
exists e1 x1 x2 x3.(n_beach(x2) & of(x2,x3) & n_sandy(x3) & n_baby(x1) & on(e1,x2) & Actor(e1,x1) & v_sit(e1))
exists p1 x1 x3.(n_beach(x3) & -exists x2.((x1 = x2) & on(x2,x3) & n_human(x2)))