A waterskier is waving at the camera happily.
A skier is waving.
The skier who is waving is a waterskier.
exists e1 s1 x1 x2.(n_camera(x2) & a_happily(s1) & Manner(e1,s1) & at(e1,x2) & Actor(e1,x1) & v_wave(e1) & n_waterskier(x1))
exists e1 x1.(Actor(e1,x1) & v_wave(e1) & n_skier(x1))