Photographers taking pictures of each other.
Some people have cameras.
Photographers have cameras.
exists x1 x2 x3.(a_topic(x1) & all x4.(n_other(x4) -> exists e1.(Theme(e1,x3) & Actor(e1,x2) & v_take(e1) & of(x3,x4))) & n_picture(x3) & (x1 = x2) & n_photographer(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_camera(x2) & n_people(x1))