Someone sits with orange and black tights at an outdoor performance.
The person is a girl
Someone does not imply girl.
exists e1 s1 s2 x1 x2 x3 x4.(at(e1,x4) & n_performance(x4) & a_outdoor(s2) & Theme(s2,x4) & with(e1,x2) & n_tights(x2) & a_black(s1) & Theme(s1,x2) & of(x2,x3) & n_orange(x3) & Actor(e1,x1) & v_sit(e1) & n_person(x1))
exists p1 x1.(n_person(x1) & exists x2.((x1 = x2) & n_girl(x2)))