A surfer is being splashed by an ocean wave.
The person is standing on a surfboard.
You can not infer they are on a surfboard.
exists e1 x1 x2 x3.(Actor(e1,x2) & n_wave(x2) & of(x2,x3) & n_ocean(x3) & Theme(e1,x1) & v_splash(e1) & n_surfer(x1))
exists e1 x1 x2.(n_person(x1) & on(e1,x2) & n_surfboard(x2) & Actor(e1,x1) & v_stand(e1))