A girl plays her guitar on a dark stage.
The person is playing an instrument
A girl is a person and her guitar is an instrument.
exists e1 s1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & a_dark(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & of(x2,x1) & n_female(x1) & n_girl(x1))
exists e1 x1 x2.(n_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_instrument(x2))