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| author | Simon-Kor <52245124+Simon-Kor@users.noreply.github.com> | 2024-06-25 00:06:14 +0200 |
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| committer | Simon-Kor <52245124+Simon-Kor@users.noreply.github.com> | 2024-06-25 00:06:14 +0200 |
| commit | c19415b970d502d662eb10c403728fa41cdbe03e (patch) | |
| tree | cfa9ce66b116403f871a3b424d2bbffba045b0d8 /library/topology/separation.tex | |
| parent | 44d4c1c50ba6e0f12a2f4fdd204b315a15e434db (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.tex | 98 |
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} |
