A biker jumps an obstacle.
A biker jumps an obstacle at a bike rally.
Not all biker jumps an obstacle at a bike rally.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_jump(e1) & n_obstacle(x2) & n_biker(x1))
exists e1 x1 x2 x3 x4.(at(e1,x3) & n_rally(x3) & of(x3,x4) & n_bike(x4) & Theme(e1,x2) & Actor(e1,x1) & v_jump(e1) & n_obstacle(x2) & n_biker(x1))