A couple of people working around a pile of rocks.
People are playing on a playground.
People cannot be working and playing at the same time.
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & around(e1,x4) & of(x4,x5) & n_rock(x5) & n_pile(x4) & Actor(e1,x3) & v_work(e1) & (x1 = x3) & of(x1,x2) & n_people(x2) & n_couple(x1))
exists e1 x1 x2.(on(e1,x2) & n_playground(x2) & Actor(e1,x1) & v_play(e1) & n_people(x1))