Two girls in blue dresses dance.
Girls in yellow dresses dance.
The dresses cannot be both yellow and blue.
exists s1 x1 x2 x3.(a_topic(x1) & in(x1,x2) & n_dance(x2) & of(x2,x3) & n_dress(x3) & a_blue(s1) & Theme(s1,x2) & n_girl(x1) & card_eq_2(x1))
exists s1 x1 x2 x3.(a_topic(x1) & in(x1,x2) & n_dance(x2) & of(x2,x3) & n_dress(x3) & a_yellow(s1) & Theme(s1,x2) & n_girl(x1))