Two construction workers working on a rooftop.
Men working on a roof.
Two construction workers could be men which is the plural version of man.
exists e1 x1 x2 x3.(on(e1,x3) & n_rooftop(x3) & Actor(e1,x1) & v_work(e1) & n_worker(x1) & of(x1,x2) & n_construction(x2) & card_eq_2(x1))
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_roof(x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_man(x1))