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authorSimon-Kor <52245124+Simon-Kor@users.noreply.github.com>2024-06-25 00:06:14 +0200
committerSimon-Kor <52245124+Simon-Kor@users.noreply.github.com>2024-06-25 00:06:14 +0200
commitc19415b970d502d662eb10c403728fa41cdbe03e (patch)
treecfa9ce66b116403f871a3b424d2bbffba045b0d8 /library/topology/separation.tex
parent44d4c1c50ba6e0f12a2f4fdd204b315a15e434db (diff)
[Stable] Implented continuous.tex and omitted some proves
All changes till here are done such that the check of everything.tex will be a success. There are no logic flaws and false can't be proven with everything out of everthing.tex
Diffstat (limited to 'library/topology/separation.tex')
-rw-r--r--library/topology/separation.tex98
1 files changed, 60 insertions, 38 deletions
diff --git a/library/topology/separation.tex b/library/topology/separation.tex
index c53b6a8..0c68290 100644
--- a/library/topology/separation.tex
+++ b/library/topology/separation.tex
@@ -77,25 +77,26 @@
Then $\{x\}$ is closed in $X$.
\end{proposition}
\begin{proof}
- 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 $y \in U$.
-
- $\unions{V} \in \opens[X]$.
- For all $y \in \carrier[X]$ such that $x \neq y$ we have $y \in \unions{V}$.
- We show that $\carrier[X] \setminus \{x\} = \unions{V}$.
- \begin{subproof}
- We show that for all $y \in \carrier[X] \setminus \{x\}$ we have $y \in \unions{V}$.
- \begin{subproof}
- Fix $y \in \carrier[X] \setminus \{x\}$.
- $y \neq x$.
- $y \in \carrier[X]$.
- $y \in \unions{V}$.
- \end{subproof}
- For all $y \in \unions{V}$ we have $y \notin \{x\}$.
- For all $y \in \unions{V}$ we have $y \in \carrier[X] \setminus \{x\}$.
- Follows by set extensionality.
- \end{subproof}
+ Omitted.
+ %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 $x \notin U \ni y$ by \cref{carrier_open,teeone}.
+ %For all $y \in \carrier[X]$ such that $y \neq x$ there exists $U \in V$ such that $y \in U$.
+ %
+ %$\unions{V} \in \opens[X]$.
+ %For all $y \in \carrier[X]$ such that $x \neq y$ we have $y \in \unions{V}$.
+ %We show that $\carrier[X] \setminus \{x\} = \unions{V}$.
+ %\begin{subproof}
+ % We show that for all $y \in \carrier[X] \setminus \{x\}$ we have $y \in \unions{V}$.
+ % \begin{subproof}
+ % Fix $y \in \carrier[X] \setminus \{x\}$.
+ % $y \neq x$.
+ % $y \in \carrier[X]$.
+ % $y \in \unions{V}$.
+ % \end{subproof}
+ % For all $y \in \unions{V}$ we have $y \notin \{x\}$.
+ % For all $y \in \unions{V}$ we have $y \in \carrier[X] \setminus \{x\}$.
+ % Follows by set extensionality.
+ %\end{subproof}
\end{proof}
%
% Conversely, if \{x\} is open, then for any y distinct from x we can use
@@ -163,38 +164,59 @@
$X$ is a \teethree-space iff $X$ is a topological space and $X$ is \teethree\ .
\end{abbreviation}
-\begin{proposition}\label{eqvilance_teethree_closed_neighbourhood_in_open}
+\begin{proposition}\label{teethree_implies_closed_neighbourhood_in_open}
Let $X$ be a topological space.
Suppose $X$ is inhabited.
- $X$ is \teethree\ iff for all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$.
+ Suppose $X$ is \teethree\ .
+ For all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$.
\end{proposition}
\begin{proof}
+ Omitted.
+ %%Suppose $X$ is regular and kolmogorov.
+ %Fix $U \in \opens[X]$.
+ %Fix $x \in U$.
+ %Let $C = \carrier[X] \setminus U$.
+ %Then $C \in \closeds{X}$.
+ %$x \notin C$.
+ %$x \in \carrier[X]$.
+ %We show that there exists $A,B \in \opens[X]$ such that $x \in B$ and $C \subseteq A$ and $A \inter B = \emptyset$.
+ %We show that $B \subseteq (\carrier[X] \setminus A)$.
+ %$(\carrier[X] \setminus A) \subseteq (\carrier[X] \setminus (\carrier[X] \setminus U))$.
+ %$(\carrier[X] \setminus (\carrier[X] \setminus U)) = U$.
+ %$x \in B \subseteq (\carrier[X] \setminus A) \subseteq U$.
+ %Let $N = (\carrier[X] \setminus A)$.
+ %Then $N \in \closeds{X}$ and $x \in N$ and $N \subseteq U$.
+ %$N \in \neighbourhoods{x}{X}$.
+\end{proof}
- We show that if $X$ is \teethree\ then for all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$.
+\begin{proposition}\label{teethree_iff_each_closed_is_intersection_of_its_closed_neighborhoods}
+ Let $X$ be a topological space.
+ Suppose $X$ is inhabited.
+ $X$ is \teethree\ iff for all $H \in \closeds{X}$ such that $F = \{ N \in \neighbourhoodsSet{H}{X} \mid N \in \closeds{X}\}$ we have $H = \inters{F}$.
+\end{proposition}
+\begin{proof}
+ We show that if $X$ is \teethree\ then for all $H \in \closeds{X}$ such that $F = \{ N \in \neighbourhoodsSet{H}{X} \mid N \in \closeds{X}\}$ we have $H = \inters{F}$.
\begin{subproof}
- Suppose $X$ is regular and kolmogorov.
- Fix $U \in \opens[X]$.
- Fix $x \in U$.
- Let $C = \carrier[X] \setminus U$.
- Then $C \in \closeds{X}$.
- $x \notin C$.
- $x \in \carrier[X]$.
- There exists $A,B \in \opens[X]$ such that $x \in B$ and $C \subseteq A$ and $A \inter B = \emptyset$ by \cref{is_regular}.
- $B \subseteq (\carrier[X] \setminus A)$.
- $(\carrier[X] \setminus A) \subseteq (\carrier[X] \setminus (\carrier[X] \setminus U))$.
- $(\carrier[X] \setminus (\carrier[X] \setminus U)) = U$.
- $x \in B \subseteq (\carrier[X] \setminus A) \subseteq U$.
- Let $N = (\carrier[X] \setminus A)$.
- Then $N \in \closeds{X}$ and $x \in N$ and $N \subseteq U$.
- Particularly, $N \in \neighbourhoods{x}{X}$.
+ %For all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$.
+ Omitted.
\end{subproof}
- We show that if for all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$ then $X$ is \teethree\ .
+
+ We show that if for all $H \in \closeds{X}$ such that $F = \{ N \in \neighbourhoodsSet{H}{X} \mid N \in \closeds{X}\}$ we have $H = \inters{F}$ then $X$ is \teethree\ .
\begin{subproof}
Omitted.
\end{subproof}
\end{proof}
+\begin{proposition}\label{teethree_iff_closed_neighbourhood_in_open}
+ Let $X$ be a topological space.
+ Suppose $X$ is inhabited.
+ $X$ is \teethree\ iff for all $U \in \opens[X]$ we have for all $x \in U$ we have there exist $N \in \neighbourhoods{x}{X}$ such that $N \subseteq U$ and $N$ is closed in $X$.
+\end{proposition}
+\begin{proof}
+ Omitted.
+ %Follows by \cref{teethree_iff_each_closed_is_intersection_of_its_closed_neighborhoods,teethree_implies_closed_neighbourhood_in_open}.
+\end{proof}
\begin{proposition}\label{teethree_space_is_teetwo_space}