Two hockey players are skating on the ice.
two people playing ice hockey
If two hockey players are playing on ice it implies they are playing ice hockey.
exists e1 x1 x2 x3.(n_ice(x3) & on(e1,x3) & Actor(e1,x1) & v_skate(e1) & n_player(x1) & of(x1,x2) & n_hockey(x2) & card_eq_2(x1))
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_play(e1) & n_hockey(x3) & of(x3,x4) & n_ice(x4) & (x1 = x2) & n_people(x1) & card_eq_2(x1))