A variety of people are running in a race.
people running a race
To refer to the runners as people is a more general way to refer to them as a variety of people.
exists e1 x1 x2 x3.(in(e1,x3) & n_race(x3) & Actor(e1,x1) & v_run(e1) & of(x1,x2) & n_people(x2) & n_variety(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_run(e1) & n_race(x3) & (x1 = x2) & n_people(x1))