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Diffstat (limited to 'library/topology/separation.tex')
| -rw-r--r-- | library/topology/separation.tex | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/library/topology/separation.tex b/library/topology/separation.tex index 530a51f..535a51f 100644 --- a/library/topology/separation.tex +++ b/library/topology/separation.tex @@ -75,11 +75,8 @@ Let $X$ be a \teeone-space. Assume $x \in \carrier[X]$. Then $\{x\}$ is closed in $X$. - %Then for all $x\in\carrier[X]$ we have $\{x\}$ is closed in $X$. Ambigus Phrase. if Omitted is ereased. \end{proposition} \begin{proof} - %Omitted. - %Fix $x \in X$. Let $V = \{ U \in \opens[X] \mid x \notin U\}$. For all $y \in \carrier[X]$ such that $x \neq y$ there exist $U \in \opens[X]$ such that $x \notin U \ni y$. For all $y \in \carrier[X]$ such that $y \neq x$ there exists $U \in V$ such that $y \in U$. @@ -99,13 +96,6 @@ For all $y \in \unions{V}$ we have $y \in \carrier[X] \setminus \{x\}$. Follows by set extensionality. \end{subproof} - % Let $U_{y} \in \opens[X]$ such that $x \neq y \in X$. Error: unexpected '{' expecting digit - %For all $y$ there exists $U$ such that $x \neq y$ and $y \in U$ and $U \in \opens[X]$. - - % TODO - % Choose for every y distinct from x and open subset U_y containing y but not x. - % The union U of all the U_y is open. - % {x} is the complement of U in \carrier[X]. \end{proof} % % Conversely, if \{x\} is open, then for any y distinct from x we can use |
