A man and a woman walking in a field.
A husband and wife walk in a field.
Not all man and woman walking in a field are husband and wife.
exists s1 x1 x2 x3 x4.(a_topic(s1) & subset_of(x2,s1) & in(x2,x4) & n_field(x4) & n_walking(x2) & of(x2,x3) & n_woman(x3) & subset_of(x1,s1) & n_man(x1))
exists e1 x1 x2 x3 x4.(in(e1,x4) & n_field(x4) & Actor(e1,x1) & v_walk(e1) & n_wife(x3) & n_husband(x2) & subset_of(x3,x1) & subset_of(x2,x1))