Three people racing on ice skates.
People on ice skates
Three people could simply be called people.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_skate(x3) & of(x3,x4) & n_ice(x4) & Actor(e1,x2) & v_race(e1) & (x1 = x2) & n_people(x1) & card_eq_3(x1))
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_skate(x2) & of(x2,x3) & n_ice(x3) & n_people(x1))