Theorem
If
is a Hausdorff space, then every convergent sequence in
has a unique limit.
Proof
Let
be a convergent sequence in
with limits![]()
Since
is a Hausdorff space open sets
and
exist such that![]()
Since
converges to![]()
![]()
Since
converges to![]()
![]()
Let
then
and
so
- a contradiction since![]()
Hence every convergent sequence in
has a unique limit.