A little boy takes a picture at the park.
A boy is at a park with his family.
The fact that the little boy takes a picture at a park doesn't mean he is with his family.  He could be with any group of people.
exists e1 s1 x1 x2 x3.(n_park(x3) & Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & at(x2,x3) & n_picture(x2) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists p1 x1 x3.(exists x2.(at(x1,x2) & with(x2,x3) & n_park(x2)) & n_family(x3) & of(x3,x1) & n_male(x1) & n_boy(x1))