A man and woman getting married.
The man and woman are brother and sister.
The man and woman cannot be both brother and sister and getting married.
exists e1 p1 s1 x1 x2 x3.(a_topic(s1) & exists e2.(Theme(e2,x3) & v_marry(e2)) & Topic(e1,p1) & Actor(e1,x3) & v_get(e1) & (s1 = x3) & n_woman(x2) & n_man(x1) & subset_of(x2,s1) & subset_of(x1,s1))
exists p1 x1 x2 x3.(n_woman(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1) & exists x4 x5 x6.((x1 = x4) & subset_of(x6,x4) & n_sister(x6) & subset_of(x5,x4) & n_brother(x5)))