A person is riding a surfboard on a wave.
A person is riding a surfboard in the ocean.
Waves are in the ocean.
exists e1 x1 x2 x3.(on(e1,x3) & n_wave(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_surfboard(x2) & n_person(x1))
exists e1 x1 x2 x3.(n_ocean(x3) & in(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_surfboard(x2) & n_person(x1))