Two men sit at work computers and work at night.
Two men working on a program.
Not all men are sitting working on their computers are working on a program.
exists e1 x1 x2 x3 x4 x5 x6.(at(e1,x6) & n_night(x6) & at(e1,x2) & subset_of(x5,x2) & n_work(x5) & subset_of(x3,x2) & n_computer(x3) & of(x3,x4) & n_work(x4) & Actor(e1,x1) & v_sit(e1) & n_man(x1) & card_eq_2(x1))
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_program(x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_man(x1) & card_eq_2(x1))