theorem Th83: :: JORDAN1A:83

for n being Nat
for C being connected compact non horizontal non vertical Subset of (TOP-REAL 2)
for p, x being Point of (TOP-REAL 2) st x in E-most C & p in (east_halfline x) /\ (L~ (Cage (C,n))) holds
p `1 = E-bound (L~ (Cage (C,n)))