A person underwater using a camera.
The person is riding a horse
A person cannot ride a horse underwater.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_use(e1) & n_camera(x4) & (x1 = x3) & Time(x1,x2) & n_underwater(x2) & n_person(x1))
exists e1 x1 x2.(n_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2))