The lights at night in the city.
The city has power.
In order for a city to have lights at night, the city has to have some sort of power.
exists x1 x2 x3.(n_city(x3) & n_light(x1) & a_topic(x1) & at(x1,x2) & in(x2,x3) & n_night(x2))
exists e1 x1 x2.(n_city(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_power(x2))