a skateboarder doing a trick
A boy loiters outside a mall on his bike.
A skateboarder doing a trick is not a boy loitering with his bike.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & n_trick(x3) & (x1 = x2) & n_skateboarder(x1))
exists e1 x1 x2 x3.(outside(e1,x2) & on(x2,x3) & n_bike(x3) & of(x3,x1) & n_male(x1) & n_mall(x2) & Actor(e1,x1) & v_loiter(e1) & n_boy(x1))