A man is firing a handgun.
A man discharges firearm.
In order to discharge a firearm you must be holding it.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_fire(e1) & n_handgun(x2) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_discharge(e1) & n_firearm(x2) & n_man(x1))