A person is surfing on a large wave.
A person is surfing.
person is surfing simply means person is surfing
exists e1 s1 x1 x2.(on(e1,x2) & n_wave(x2) & a_large(s1) & Theme(s1,x2) & Actor(e1,x1) & v_surf(e1) & n_person(x1))
exists e1 x1.(Actor(e1,x1) & v_surf(e1) & n_person(x1))