A man and woman are standing near a wall in the winter.
Nobody near a wall.
There is either a man and a woman near a wall, or nobody near a wall.
exists e1 x1 x2 x3 x4 x5.(n_winter(x5) & in(e1,x5) & near(e1,x4) & n_wall(x4) & Actor(e1,x1) & v_stand(e1) & n_woman(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1))
-exists x1 x2.(a_topic(x1) & near(x1,x2) & n_wall(x2) & n_person(x1))