A young girl sits on the edge of a sink.
a girl sits on a sink
in a both sentence edge and sink are not same.
exists e1 s1 x1 x2 x3.(n_edge(x2) & on(e1,x2) & of(x2,x3) & n_sink(x3) & Actor(e1,x1) & v_sit(e1) & n_girl(x1) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2.(on(e1,x2) & n_sink(x2) & Actor(e1,x1) & v_sit(e1) & n_girl(x1))