A man and a woman smile for the camera.
The man is the boyfriend of the woman.
Not every man is the boyfriend of a woman.
exists s1 x1 x2 x3 x4.(n_camera(x4) & a_topic(s1) & subset_of(x2,s1) & for(x2,x4) & n_smile(x2) & of(x2,x3) & n_woman(x3) & subset_of(x1,s1) & n_man(x1))
exists p1 x1 x2 x3.(n_woman(x3) & n_boyfriend(x2) & n_man(x1) & (x1 = x2) & of(x2,x3))