People walking through the mall.
People are shopping in the mall on a sale day.
The people may just be walking and not shopping.
exists e1 x1 x2 x3.(n_mall(x3) & a_topic(x1) & through(e1,x3) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1))
exists e1 x1 x2 x3 x4.(n_mall(x2) & on(e1,x3) & n_day(x3) & of(x3,x4) & n_sale(x4) & in(e1,x2) & Actor(e1,x1) & v_shop(e1) & n_people(x1))