Two children are playing on a makeshift barrel swing.
The kids are playing on the swing because it's the only thing they have to do.
It is not implied that playing on a barrel swing is the only thing the kids have to do.
exists e1 x1 x2 x3 x4.(on(e1,x2) & n_swing(x2) & of(x2,x4) & n_barrel(x4) & of(x2,x3) & n_makeshift(x3) & Actor(e1,x1) & v_play(e1) & n_child(x1) & card_eq_2(x1))
exists e1 p1 x1 x2.(n_thing(x2) & n_thing(x2) & all x3.(n_thing(x3) -> (x2 = x3)) & n_thing(x2) & n_swing(x2) & n_kid(x1) & exists p2 e2 p3.((x2 = x2) & Topic(e2,p3) & Actor(e2,x2) & v_have(e2) & exists e3 x4.(Theme(e3,x4) & Actor(e3,x2) & v_do(e3) & (x2 = x4))) & because(e1,p1) & on(e1,x2) & Actor(e1,x1) & v_play(e1))