Welders working at night with sparks flying.
The welders are working with machines.
sparks flying implies they are using machines.
exists e1 e2 x1 x2 x3.(Actor(e2,x3) & v_fly(e2) & with(e1,x3) & n_sparks(x3) & at(e1,x2) & n_night(x2) & Actor(e1,x1) & v_work(e1) & n_welder(x1))
exists e1 x1 x2.(n_welder(x1) & with(e1,x2) & n_machine(x2) & Actor(e1,x1) & v_work(e1))