for C being connected compact non horizontal non vertical Subset of (TOP-REAL 2)
for n being Nat holds (L~ ((Cage (C,n)) -: (E-max (L~ (Cage (C,n)))))) /\ (L~ ((Cage (C,n)) :- (E-max (L~ (Cage (C,n)))))) = {(N-min (L~ (Cage (C,n)))),(E-max (L~ (Cage (C,n))))}