Men working with electrical equipment on a building.
No one is working with electrical equipment.
There can only either be men or no one.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_building(x4) & with(e1,x3) & n_equipment(x3) & a_electrical(s1) & Theme(s1,x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_man(x1))
-exists e1 s1 x1 x2.(with(e1,x2) & n_equipment(x2) & a_electrical(s1) & Theme(s1,x2) & Actor(e1,x1) & v_work(e1) & n_one(x1))