A man on a surfboard rides the waves.
A man is being eaten by a shark.
The man is either on a surfboard rides the waves or being eaten by a shark.
exists e1 x1 x2 x3.(n_wave(x3) & Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & on(x1,x2) & n_surfboard(x2) & n_man(x1))
exists e1 x1 x2.(Actor(e1,x2) & n_shark(x2) & Theme(e1,x1) & v_eat(e1) & n_man(x1))