Two people are riding motorcycle in a race.
Two people standing on a roof.
If they are riding motorcycle, they can't be standing.
exists e1 x1 x2 x3.(in(e1,x3) & n_race(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_motorcycle(x2) & n_people(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_roof(x3) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_people(x1) & card_eq_2(x1))