A crossing guard wearing a hat.
The person is ensuring safety is observed.
A crossing gaurd is someone ensuring safety.
exists e2 e1 x1 x2 x3.(a_topic(x1) & Theme(e2,x3) & Actor(e2,x2) & v_wear(e2) & n_hat(x3) & (x1 = x2) & n_guard(x1) & Actor(e1,x1) & v_cross(e1))
exists e1 e2 x1 x2 x3.(n_person(x1) & Theme(e2,x1) & v_observe(e2) & Theme(e1,x3) & Actor(e1,x2) & v_ensure(e1) & n_safety(x3) & (x1 = x2))