Two firemen are standing by a firetruck.
The men are firefighters.
The two men are standing on a firetruck so they are most likely firemen inspecting, fixing, or cleaning their truck; or at the scene at a fire using the ladder.
exists e1 x1 x2.(by(e1,x2) & n_firetruck(x2) & Actor(e1,x1) & v_stand(e1) & n_fireman(x1) & card_eq_2(x1))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_firefighter(x2)))