A group of adults are walking.
People are driving to lunch.
People walking cannot be driving the same time.
exists e1 x1 x2.(Actor(e1,x1) & v_walk(e1) & of(x1,x2) & n_adult(x2) & n_group(x1))
exists e1 x1 x2.(to(e1,x2) & n_lunch(x2) & Actor(e1,x1) & v_drive(e1) & n_people(x1))