A boy doing a skateboard trick
The boy is a skater.
A boy doing a skateboard trick implies that he is a skater.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & n_trick(x3) & of(x3,x4) & n_skateboard(x4) & (x1 = x2) & n_boy(x1))
exists p1 x1.(n_boy(x1) & exists x2.((x1 = x2) & n_skater(x2)))