a man doing tricks on a bmx bike
A man is in a bmx competition.
he might not be doing tricks in a competition, it could be for leisure
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & on(e1,x4) & n_bike(x4) & of(x4,x5) & n_bmx(x5) & Theme(e1,x3) & Actor(e1,x2) & v_do(e1) & n_trick(x3) & (x1 = x2) & n_man(x1))
exists p1 x1.(exists s1 x2.(in(x1,x2) & n_competition(x2) & a_bmx(s1) & Theme(s1,x2)) & n_man(x1))