Some party goers pose in their costumes at a halloween party.
they are at a christmas party
Halloween party and Christmas party cannot exist simultaneously.
exists e1 x1 x2 x3 x4 x5.(at(e1,x4) & n_party(x4) & of(x4,x5) & n_halloween(x5) & in(e1,x3) & n_costume(x3) & of(x3,x1) & n_thing(x1) & Actor(e1,x1) & v_pose(e1) & n_goer(x1) & of(x1,x2) & n_party(x2))
exists p1 x1.(n_thing(x1) & exists x2 x3.(at(x1,x2) & n_party(x2) & of(x2,x3) & n_christmas(x3)))