Nine girls on stage performing in red dresses.
On stage some girls perform.
There is nothing from the first sentence that indicates only some of the girls performed.
exists e1 s1 x1 x2 x3.(in(e1,x3) & n_dress(x3) & a_red(s1) & Theme(s1,x3) & Actor(e1,x1) & v_perform(e1) & on(x1,x2) & n_stage(x2) & n_girl(x1) & card_eq_9(x1))
exists e1 x1 x2.(on(e1,x2) & n_stage(x2) & Actor(e1,x1) & v_perform(e1) & n_girl(x1))