Two men in safety harnesses work together.
Two men are ice skating.
People cannot be ice skating and completing work in safety harnesses at the same time.
exists e1 s1 x1 x2 x3.(a_together(s1) & Manner(e1,s1) & Actor(e1,x1) & v_work(e1) & in(x1,x2) & n_harness(x2) & of(x2,x3) & n_safety(x3) & n_man(x1) & card_eq_2(x1))
exists e1 x1 x2.(Time(e1,x2) & n_ice(x2) & Actor(e1,x1) & v_skate(e1) & n_man(x1) & card_eq_2(x1))