- #1
alligatorman
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Consider the set of rational numbers, under the usual metric d(x,y)=|x-y|
I am pretty sure that this space is totally disconnected, but I can't convince myself that the set {x} U {y} is a disconnected set.
It seems obvious, but I can't find two non-empty disjoint open sets U,V such that U U V = {x} U {y}.
I am sure {x},{y} are not open sets, so I need something bigger.
Is the total disconnection only true if the the set Q is a relative topology of R?
Thanks
I am pretty sure that this space is totally disconnected, but I can't convince myself that the set {x} U {y} is a disconnected set.
It seems obvious, but I can't find two non-empty disjoint open sets U,V such that U U V = {x} U {y}.
I am sure {x},{y} are not open sets, so I need something bigger.
Is the total disconnection only true if the the set Q is a relative topology of R?
Thanks