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Theorem - A universal net
in a compact space is convergent.
Proof : Suppose by contradiction that
was not convergent. Then for every we would find neighborhoods such that
The collection of all this neighborhoods cover , and as is compact, a finite number
also cover .
The net
is not eventually in so it must be eventually in (because it is a universal net). Therefore we can find
such that
Because we have a finite number
we can find
such that
for each
.
Then
for all , i.e.
for all . But
cover and thus we have a contradiction. 
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