Two children are climbing stairs which lead to an airplane.
Children are sitting inside an airplane.
Climbing stairs to an airplane contradicts sitting inside an airplane.
exists e2 e1 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))
exists e1 x1 x2.(inside(e1,x2) & n_airplane(x2) & Actor(e1,x1) & v_sit(e1) & n_child(x1))