A man on a motor cross bike jumping a dirt mound.
A man is in a motor cross competition.
Sentence two may be talking about different man.
exists e1 x1 x2 x3 x4 x5 x6 x7.(a_topic(x1) & on(x1,x2) & Theme(e1,x6) & Actor(e1,x5) & v_jump(e1) & n_mound(x6) & of(x6,x7) & n_dirt(x7) & (x2 = x5) & n_bike(x2) & of(x2,x4) & n_cross(x4) & of(x2,x3) & n_motor(x3) & n_man(x1))
exists p1 x1.(exists x2 x3 x4.(in(x1,x2) & n_competition(x2) & of(x2,x4) & n_cross(x4) & of(x2,x3) & n_motor(x3)) & n_man(x1))