People walking in a supermarket.
People are buying items
buying is to get objects of ones own wish
exists e1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_supermarket(x3) & Actor(e1,x2) & v_walk(e1) & (x1 = x2) & n_people(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_buy(e1) & n_item(x2) & n_people(x1))