A man jumping on a skiing board.
A man is doing a trick on a board.
Jumping on a skiing board doesn't have to be part of a trick.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_board(x3) & of(x3,x4) & n_skiing(x4) & Actor(e1,x2) & v_jump(e1) & (x1 = x2) & n_man(x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & on(x2,x3) & n_board(x3) & n_trick(x2) & n_man(x1))