A group of people are talking in a public area.
A group of people are talking about sports in a public area.
Just because are in  public area it does not mean they are talking about sports.
exists e1 s1 x1 x2 x3.(in(e1,x3) & n_area(x3) & a_public(s1) & Theme(s1,x3) & Actor(e1,x1) & v_talk(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists e1 s1 x1 x2 x3 x4.(about(e1,x3) & in(x3,x4) & n_area(x4) & a_public(s1) & Theme(s1,x4) & n_sport(x3) & Actor(e1,x1) & v_talk(e1) & of(x1,x2) & n_people(x2) & n_group(x1))