Two men wearing headphones are working with machinery.
The men are using jackhammers.
The two men could be in a steel mill and not working with jackhammers. you can't imply that.
exists e1 e2 x1 x2 x3 x4.(with(e2,x4) & n_machinery(x4) & Actor(e2,x1) & v_work(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_headphone(x3) & (x1 = x2) & n_man(x1) & card_eq_2(x1))
exists e1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_use(e1) & n_jackhammer(x2))