To prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$.Show the $operatornameint(A)$ is open.Give an example of a metric space $(X,d)$ and $Asubseteq X$ such that $textint(overlineA)notsubseteqoverlinetextint(A)$ and vice versaBoundary of Boundary of a set?Proving that $operatornamecl(operatornameint(Y))=operatornamecl(Y)$ for subsets $Y$ of a topological space $X$If $operatornameBdA cap operatornameBdB= emptyset$, show that $operatornameint(A)cupoperatornameint(B)=operatornameint(Acup B)$Does $operatornameint(f^-1[A]) subseteq f^−1 [operatornameint(A)]$ hold for continuous $f$?prove or disprove on topological space the following:Prove interior point is a topological invariantIf $A$ is open then $textInt(A)=A$Prove that $A$ is open if and only if $A=operatornameintA$
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To prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$.
Show the $operatornameint(A)$ is open.Give an example of a metric space $(X,d)$ and $Asubseteq X$ such that $textint(overlineA)notsubseteqoverlinetextint(A)$ and vice versaBoundary of Boundary of a set?Proving that $operatornamecl(operatornameint(Y))=operatornamecl(Y)$ for subsets $Y$ of a topological space $X$If $operatornameBdA cap operatornameBdB= emptyset$, show that $operatornameint(A)cupoperatornameint(B)=operatornameint(Acup B)$Does $operatornameint(f^-1[A]) subseteq f^−1 [operatornameint(A)]$ hold for continuous $f$?prove or disprove on topological space the following:Prove interior point is a topological invariantIf $A$ is open then $textInt(A)=A$Prove that $A$ is open if and only if $A=operatornameintA$
$begingroup$
Let $(X,tau)$ be a topological space, $A$ be a subset of $X$, $operatornamecl(A)$ and $operatornameint(A)$ denote the closure and interior of $A$, respectively. I want to find a relation between $operatornameint(operatornamecl(A))$ and $operatornamecl(operatornameintA))$. By an example I found that $operatornamecl(operatornameintA))nsubseteq operatornameint(operatornamecl(A))$, but I could not prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$. Any hint to prove or disprove it?
general-topology
$endgroup$
add a comment |
$begingroup$
Let $(X,tau)$ be a topological space, $A$ be a subset of $X$, $operatornamecl(A)$ and $operatornameint(A)$ denote the closure and interior of $A$, respectively. I want to find a relation between $operatornameint(operatornamecl(A))$ and $operatornamecl(operatornameintA))$. By an example I found that $operatornamecl(operatornameintA))nsubseteq operatornameint(operatornamecl(A))$, but I could not prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$. Any hint to prove or disprove it?
general-topology
$endgroup$
add a comment |
$begingroup$
Let $(X,tau)$ be a topological space, $A$ be a subset of $X$, $operatornamecl(A)$ and $operatornameint(A)$ denote the closure and interior of $A$, respectively. I want to find a relation between $operatornameint(operatornamecl(A))$ and $operatornamecl(operatornameintA))$. By an example I found that $operatornamecl(operatornameintA))nsubseteq operatornameint(operatornamecl(A))$, but I could not prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$. Any hint to prove or disprove it?
general-topology
$endgroup$
Let $(X,tau)$ be a topological space, $A$ be a subset of $X$, $operatornamecl(A)$ and $operatornameint(A)$ denote the closure and interior of $A$, respectively. I want to find a relation between $operatornameint(operatornamecl(A))$ and $operatornamecl(operatornameintA))$. By an example I found that $operatornamecl(operatornameintA))nsubseteq operatornameint(operatornamecl(A))$, but I could not prove or disprove $operatornameint(operatornamecl(A))subseteq operatornamecl(operatornameintA))$. Any hint to prove or disprove it?
general-topology
general-topology
edited yesterday
Henno Brandsma
112k348120
112k348120
asked yesterday
InfinityInfinity
629514
629514
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1 Answer
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$begingroup$
Hint: Take $X$ the set of real numbers and $A$ the subset of rational numbers.
$endgroup$
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1 Answer
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1 Answer
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$begingroup$
Hint: Take $X$ the set of real numbers and $A$ the subset of rational numbers.
$endgroup$
add a comment |
$begingroup$
Hint: Take $X$ the set of real numbers and $A$ the subset of rational numbers.
$endgroup$
add a comment |
$begingroup$
Hint: Take $X$ the set of real numbers and $A$ the subset of rational numbers.
$endgroup$
Hint: Take $X$ the set of real numbers and $A$ the subset of rational numbers.
answered yesterday
TomGrubbTomGrubb
11k11539
11k11539
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