People are at a party at night.
The people are being quiet at the party.
Not a contradiction, people can be quiet at  party.
exists p1 x1 x2.(at(p1,x2) & n_night(x2) & exists x3.(at(x1,x3) & n_party(x3)) & n_people(x1))
exists s1 x1 x2.(n_party(x2) & n_people(x1) & at(s1,x2) & Theme(s1,x1) & a_quiet(s1))