People walking and running along park path.
People at a park
People might be going to or from the park rather than being at the park.
exists e1 e2 x1 x2 x3 x4.(along(e2,x3) & n_path(x3) & of(x3,x4) & n_park(x4) & Actor(e2,x2) & v_run(e2) & n_people(x2) & Actor(e1,x1) & v_walk(e1) & n_people(x1))
exists x1 x2.(a_topic(x1) & at(x1,x2) & n_park(x2) & n_people(x1))