People sitting in a vehicle.
Humans sitting.
People are humans, and one who is sitting in a vehicle is sitting.
exists e1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_vehicle(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_people(x1))
exists e1 x1.(ne_nam_humans(x1) & Actor(e1,x1) & v_sit(e1))