A car and a minivan have collided.
The road is empty.
The road is not empty if there are 2 cars collided.
exists e1 x1 x2 x3.(Actor(e1,x1) & v_collide(e1) & subset_of(x3,x1) & n_minivan(x3) & subset_of(x2,x1) & n_car(x2))
exists s1 x1.(n_road(x1) & Theme(s1,x1) & a_empty(s1))