Theorem
|The intersection of a closed set
with a compact set
is compact.
Proof
Let
be an open cover of
so that![]()

Then
and since
is closed
is an open cover of![]()
is compact so a finite subcover
of A exists.
Hence
and
is compact.
Theorem
|The intersection of a closed set
with a compact set
is compact.
Proof
Let
be an open cover of
so that![]()

Then
and since
is closed
is an open cover of![]()
is compact so a finite subcover
of A exists.
Hence
and
is compact.