Two kids are swinging on a swing while standing.
The two kids are brothers.
The two kids need not be brothers, they could also be friends.
exists e2 e1 x1 x2.(while(e1,e2) & Actor(e2,x1) & v_stand(e2) & on(e1,x2) & n_swing(x2) & Actor(e1,x1) & v_swing(e1) & n_kid(x1) & card_eq_2(x1))
exists p1 x1.(n_kid(x1) & card_eq_2(x1) & exists x2.((x1 = x2) & n_brother(x2)))