A man holding a steel rod forges a fire.
A man holding a rod starts a fire on Saturday night.
The first sentence implies nothing about the fire being on Saturday.
exists e2 e1 x1 x2 x3 x4 x5.(Theme(e2,x5) & Actor(e2,x1) & v_forge(e2) & n_fire(x5) & Theme(e1,x3) & Actor(e1,x2) & v_hold(e1) & n_rod(x3) & of(x3,x4) & n_steel(x4) & (x1 = x2) & n_man(x1))
exists e2 e1 x1 x2 x3 x4 x5 x6.(on(e2,x5) & n_night(x5) & (x5 = x6) & ne_tim_saturday(x6) & Theme(e2,x4) & Actor(e2,x1) & v_start(e2) & n_fire(x4) & Theme(e1,x3) & Actor(e1,x2) & v_hold(e1) & n_rod(x3) & (x1 = x2) & n_man(x1))