Two people with hard hats on standing on a brick wall.
Two construction workers are working on a brick wall.
People with hard hats are not always construction workers. Standing on a wall may not be working on it.
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & with(x1,x2) & on(e1,x4) & n_wall(x4) & of(x4,x5) & n_brick(x5) & Actor(e1,x3) & v_stand(e1) & (x2 = x3) & n_hat(x2) & a_hard(s1) & Theme(s1,x2) & n_people(x1) & card_eq_2(x1))
exists e1 x1 x2 x3 x4.(on(e1,x3) & n_wall(x3) & of(x3,x4) & n_brick(x4) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2) & card_eq_2(x1))