Prove or Disprove: Closure of Int(X)=X

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The discussion centers on the mathematical proposition regarding the closure of the interior of a closed set X, specifically whether clos(int(X)) equals X. Julia posits that this statement is true but lacks a proof. A counterexample is provided, illustrating that for a singleton set {p}, which is closed in any metric topology, its interior is empty, leading to a closure that does not equal the original set X. This indicates that the proposition is false in general.

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Prove or disprove

Closure of the Interior of a closed set X is equal to X
so clos(intX)=X

I think it is true, but i don't know how to prove it

I thought that clos(int(X))=int(X)+bdy(int(X))=X


thanks,

julia
 
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Think carefully. Consider the singleton set {p} containing only the single point p. In any metric topology, such a set is closed. What is its interior? What is the closure of that interior.
 
What if the interior is non-empty?
 

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