Constructing Nested Compact Sets in a Dense Open Set

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If Gn is a dense open set for every n, then intersection Gn is not
empty.


Well I started by thinking about what dense means.
A set A contained in reals is dense if A closure = reals
So Gn closure = reals


G closure = reals.
Then GUL=reals
Then G contains all of its limit points.
Then G is infinite because otherwise it would contain only its isolated points.
We can write G={x1,x2,...}
We want to construct a sequence of nested compact sets Kn all contained in G
 
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Is there a way to go about this given my start?
 
Are you working in \mathbb{R} or an arbitrary metric space?
 
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