A group of people are waiting at a subway station.
People are flying a blimp.
One can not be flying a blimp and waiting at a subway simultaneously.
exists e1 x1 x2 x3 x4.(at(e1,x3) & n_station(x3) & of(x3,x4) & n_subway(x4) & Actor(e1,x1) & v_wait(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_fly(e1) & n_blimp(x2) & n_people(x1))