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-rw-r--r--library/topology/separation.tex10
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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