Two children are climbing stairs which lead to an airplane.
Two children board a jet on a private runway.
Not all airplanes are jets. The children can be climbing stairs on a public or private runway.
exists e1 e2 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_climb(e2) & to(e1,x4) & n_airplane(x4) & Actor(e1,x3) & v_lead(e1) & (x2 = x3) & n_stair(x2) & n_child(x1) & card_eq_2(x1))
all x1.(n_jet(x1) -> exists s1 x2 x3 x4.(a_topic(x2) & on(x2,x4) & n_runway(x4) & a_private(s1) & Theme(s1,x4) & for(x2,x1) & n_board(x2) & of(x2,x3) & n_child(x3) & card_eq_2(x2)))