The gang watches some TV.
The gang are all friends.
Not all people watching TV are friends.
exists e1 x1 x2.(n_gang(x1) & Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_tv(x2))
exists p1 x1.(n_gang(x1) & all x2.(n_friend(x2) -> (x1 = x2)))