A couple attending a party.
The man and woman were at a party.
A man and women are couple who attending a party.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_attend(e1) & n_party(x3) & (x1 = x2) & n_couple(x1))
exists p1 x1 x2 x3.(n_woman(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1) & exists x4.(at(x1,x4) & n_party(x4)))