The city at night.
The city in the daylight
The city cannot be experiencing night and day at the same time.
exists x1 x2.(n_city(x1) & a_topic(x1) & at(x1,x2) & n_night(x2))
exists x1 x2.(n_daylight(x2) & n_city(x1) & a_topic(x1) & in(x1,x2))