Cargo is being loaded onto a ship.
Things are being loaded onto a cargo ship.
Cargo are things.  A ship that carries cargo is a cargo ship.
exists e1 x1 x2.(ne_nam_cargo(x1) & onto(e1,x2) & n_ship(x2) & Theme(e1,x1) & v_load(e1))
exists e1 x1 x2 x3.(onto(e1,x2) & n_ship(x2) & of(x2,x3) & n_cargo(x3) & Theme(e1,x1) & v_load(e1) & n_thing(x1))