A crowd is watching a teenager perform.
No one is watching the performance.
A crowd cannot be no one.
exists e2 e1 x1 x2 x3.(Actor(e2,x1) & v_perform(e2) & Theme(e1,x3) & Actor(e1,x2) & v_watch(e1) & n_teenager(x3) & (x1 = x2) & n_crowd(x1))
exists x2.(n_performance(x2) & -exists e1 x1.(Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_one(x1)))