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authorSimon-Kor <52245124+Simon-Kor@users.noreply.github.com>2024-09-23 01:20:05 +0200
committerSimon-Kor <52245124+Simon-Kor@users.noreply.github.com>2024-09-23 01:20:05 +0200
commit29f32e2031eafa087323d79d812a1b38ac78f977 (patch)
tree8868ac427d007062223dda4c545fc3bc9b8d9c87 /library/topology/urysohn.tex
parent1b05816322dc79b20976350393f71840c697eb46 (diff)
working commit
Diffstat (limited to 'library/topology/urysohn.tex')
-rw-r--r--library/topology/urysohn.tex140
1 files changed, 70 insertions, 70 deletions
diff --git a/library/topology/urysohn.tex b/library/topology/urysohn.tex
index ff6a231..ae03273 100644
--- a/library/topology/urysohn.tex
+++ b/library/topology/urysohn.tex
@@ -36,7 +36,7 @@ The first tept will be a formalisation of chain constructions.
% $\overline{A_{i-1}} \subset \interior{A_{i}}$.
% In this case we call the chain legal.
-\begin{definition}\label{one_to_n_set}
+\begin{definition}\label{urysohnone_one_to_n_set}
$\seq{m}{n} = \{x \in \naturals \mid m \leq x \leq n\}$.
\end{definition}
@@ -48,7 +48,7 @@ The first tept will be a formalisation of chain constructions.
% together with the existence of an indexing function.
%
%%-----------------------
-\begin{struct}\label{sequence}
+\begin{struct}\label{urysohnone_sequence}
A sequence $X$ is a onesorted structure equipped with
\begin{enumerate}
\item $\indexx$
@@ -57,8 +57,8 @@ The first tept will be a formalisation of chain constructions.
\end{enumerate}
such that
\begin{enumerate}
- \item\label{indexset_is_subset_naturals} $\indexxset[X] \subseteq \naturals$.
- \item\label{index_is_bijection} $\indexx[X]$ is a bijection from $\indexxset[X]$ to $\carrier[X]$.
+ \item\label{urysohnone_indexset_is_subset_naturals} $\indexxset[X] \subseteq \naturals$.
+ \item\label{urysohnone_index_is_bijection} $\indexx[X]$ is a bijection from $\indexxset[X]$ to $\carrier[X]$.
\end{enumerate}
\end{struct}
@@ -67,12 +67,12 @@ The first tept will be a formalisation of chain constructions.
-\begin{definition}\label{cahin_of_subsets}
+\begin{definition}\label{urysohnone_cahin_of_subsets}
$C$ is a chain of subsets iff
$C$ is a sequence and for all $n,m \in \indexxset[C]$ such that $n < m$ we have $\indexx[C](n) \subseteq \indexx[C](m)$.
\end{definition}
-\begin{definition}\label{chain_of_n_subsets}
+\begin{definition}\label{urysohnone_chain_of_n_subsets}
$C$ is a chain of $n$ subsets iff
$C$ is a chain of subsets and $n \in \indexxset[C]$
and for all $m \in \naturals$ such that $m \leq n$ we have $m \in \indexxset[C]$.
@@ -84,7 +84,7 @@ The first tept will be a formalisation of chain constructions.
% and also for the subproof of continuity of the limit.
-% \begin{definition}\label{legal_chain}
+% \begin{definition}\label{urysohnone_legal_chain}
% $C$ is a legal chain of subsets of $X$ iff
% $C \subseteq \pow{X}$. %and
% %there exist $f \in \funs{C}{\naturals}$ such that
@@ -106,49 +106,49 @@ The first tept will be a formalisation of chain constructions.
\subsection{staircase function}
-\begin{definition}\label{minimum}
+\begin{definition}\label{urysohnone_minimum}
$\min{X} = \{x \in X \mid \forall y \in X. x \leq y \}$.
\end{definition}
-\begin{definition}\label{maximum}
+\begin{definition}\label{urysohnone_maximum}
$\max{X} = \{x \in X \mid \forall y \in X. x \geq y \}$.
\end{definition}
-\begin{definition}\label{intervalclosed}
+\begin{definition}\label{urysohnone_intervalclosed}
$\intervalclosed{a}{b} = \{x \in \reals \mid a \leq x \leq b\}$.
\end{definition}
-\begin{definition}\label{intervalopen}
+\begin{definition}\label{urysohnone_intervalopen}
$\intervalopen{a}{b} = \{ x \in \reals \mid a < x < b\}$.
\end{definition}
-\begin{struct}\label{staircase_function}
+\begin{struct}\label{urysohnone_staircase_function}
A staircase function $f$ is a onesorted structure equipped with
\begin{enumerate}
\item $\chain$
\end{enumerate}
such that
\begin{enumerate}
- \item \label{staircase_is_function} $f$ is a function to $\intervalclosed{\zero}{1}$.
- \item \label{staircase_domain} $\dom{f}$ is a topological space.
- \item \label{staricase_def_chain} $C$ is a chain of subsets.
- \item \label{staircase_chain_is_in_domain} for all $x \in C$ we have $x \subseteq \dom{f}$.
- \item \label{staircase_behavoir_index_zero} $f(\indexx[C](1))= 1$.
- \item \label{staircase_behavoir_index_n} $f(\dom{f}\setminus \unions{C}) = \zero$.
- \item \label{staircase_chain_indeset} There exist $n$ such that $\indexxset[C] = \seq{\zero}{n}$.
- \item \label{staircase_behavoir_index_arbetrray} for all $n \in \indexxset[C]$
+ \item \label{urysohnone_staircase_is_function} $f$ is a function to $\intervalclosed{\zero}{1}$.
+ \item \label{urysohnone_staircase_domain} $\dom{f}$ is a topological space.
+ \item \label{urysohnone_staricase_def_chain} $C$ is a chain of subsets.
+ \item \label{urysohnone_staircase_chain_is_in_domain} for all $x \in C$ we have $x \subseteq \dom{f}$.
+ \item \label{urysohnone_staircase_behavoir_index_zero} $f(\indexx[C](1))= 1$.
+ \item \label{urysohnone_staircase_behavoir_index_n} $f(\dom{f}\setminus \unions{C}) = \zero$.
+ \item \label{urysohnone_staircase_chain_indeset} There exist $n$ such that $\indexxset[C] = \seq{\zero}{n}$.
+ \item \label{urysohnone_staircase_behavoir_index_arbetrray} for all $n \in \indexxset[C]$
such that $n \neq \zero$ we have $f(\indexx[C](n) \setminus \indexx[C](n-1)) = \rfrac{n}{ \max{\indexxset[C]} }$.
\end{enumerate}
\end{struct}
-\begin{definition}\label{legal_staircase}
+\begin{definition}\label{urysohnone_legal_staircase}
$f$ is a legal staircase function iff
$f$ is a staircase function and
for all $n,m \in \indexxset[\chain[f]]$ such that $n \leq m$ we have $f(\indexx[\chain[f]](n)) \leq f(\indexx[\chain[f]](m))$.
\end{definition}
-\begin{abbreviation}\label{urysohnspace}
+\begin{abbreviation}\label{urysohnone_urysohnspace}
$X$ is a urysohn space iff
$X$ is a topological space and
for all $A,B \in \closeds{X}$ such that $A \inter B = \emptyset$
@@ -156,49 +156,49 @@ The first tept will be a formalisation of chain constructions.
such that $A \subseteq A'$ and $B \subseteq B'$ and $A' \inter B' = \emptyset$.
\end{abbreviation}
-\begin{definition}\label{urysohnchain}
+\begin{definition}\label{urysohnone_urysohnchain}
$C$ is a urysohnchain in $X$ of cardinality $k$ iff %<---- TODO: cardinality unused!
$C$ is a chain of subsets and
for all $A \in C$ we have $A \subseteq X$ and
for all $n,m \in \indexxset[C]$ such that $n < m$ we have $\closure{\indexx[C](n)}{X} \subseteq \interior{\indexx[C](m)}{X}$.
\end{definition}
-\begin{definition}\label{urysohnchain_without_cardinality}
+\begin{definition}\label{urysohnone_urysohnchain_without_cardinality}
$C$ is a urysohnchain in $X$ iff
$C$ is a chain of subsets and
for all $A \in C$ we have $A \subseteq X$ and
for all $n,m \in \indexxset[C]$ such that $n < m$ we have $\closure{\indexx[C](n)}{X} \subseteq \interior{\indexx[C](m)}{X}$.
\end{definition}
-\begin{abbreviation}\label{infinte_sequence}
+\begin{abbreviation}\label{urysohnone_infinte_sequence}
$S$ is a infinite sequence iff $S$ is a sequence and $\indexxset[S]$ is infinite.
\end{abbreviation}
-\begin{definition}\label{infinite_product}
+\begin{definition}\label{urysohnone_infinite_product}
$X$ is the infinite product of $Y$ iff
$X$ is a infinite sequence and for all $i \in \indexxset[X]$ we have $\indexx[X](i) = Y$.
\end{definition}
-\begin{definition}\label{refinmant}
+\begin{definition}\label{urysohnone_refinmant}
$C'$ is a refinmant of $C$ iff $C'$ is a urysohnchain in $X$
and for all $x \in C$ we have $x \in C'$
and for all $y \in C$ such that $y \subset x$ we have there exist $c \in C'$ such that $y \subset c \subset x$
and for all $g \in C'$ such that $g \neq c$ we have not $y \subset g \subset x$.
\end{definition}
-\begin{abbreviation}\label{two}
+\begin{abbreviation}\label{urysohnone_two}
$\two = \suc{1}$.
\end{abbreviation}
-\begin{lemma}\label{two_in_reals}
+\begin{lemma}\label{urysohnone_two_in_reals}
$\two \in \reals$.
\end{lemma}
-\begin{lemma}\label{two_in_naturals}
+\begin{lemma}\label{urysohnone_two_in_naturals}
$\two \in \naturals$.
\end{lemma}
-\begin{inductive}\label{power_of_two}
+\begin{inductive}\label{urysohnone_power_of_two}
Define $\powerOfTwoSet \subseteq (\naturals \times \naturals)$.
\begin{enumerate}
\item $(\zero, 1) \in \powerOfTwoSet$.
@@ -206,45 +206,45 @@ The first tept will be a formalisation of chain constructions.
\end{enumerate}
\end{inductive}
-\begin{abbreviation}\label{pot}
+\begin{abbreviation}\label{urysohnone_pot}
$\pot = \powerOfTwoSet$.
\end{abbreviation}
-\begin{lemma}\label{dom_pot}
+\begin{lemma}\label{urysohnone_dom_pot}
$\dom{\pot} = \naturals$.
\end{lemma}
\begin{proof}
Omitted.
\end{proof}
-\begin{lemma}\label{ran_pot}
+\begin{lemma}\label{urysohnone_ran_pot}
$\ran{\pot} \subseteq \naturals$.
\end{lemma}
-\begin{axiom}\label{pot1}
+\begin{axiom}\label{urysohnone_pot1}
$\pot \in \funs{\naturals}{\naturals}$.
\end{axiom}
-\begin{axiom}\label{pot2}
+\begin{axiom}\label{urysohnone_pot2}
For all $n \in \naturals$ we have there exist $k\in \naturals$ such that $(n, k) \in \powerOfTwoSet$ and $\apply{\pot}{n}=k$.
%$\pot(n) = k$ iff there exist $x \in \powerOfTwoSet$ such that $x = (n,k)$.
\end{axiom}
%Without this abbreviation \pot cant be sed as a function in the standard sense
-\begin{abbreviation}\label{pot_as_function}
+\begin{abbreviation}\label{urysohnone_pot_as_function}
$\pot(n) = \apply{\pot}{n}$.
\end{abbreviation}
%Take all points, besids one but then take all open sets not containing x but all other, so \{x\} has to be closed
-\begin{axiom}\label{hausdorff_implies_singltons_closed}
+\begin{axiom}\label{urysohnone_hausdorff_implies_singltons_closed}
For all $X$ such that $X$ is Hausdorff we have
for all $x \in \carrier[X]$ we have $\{x\}$ is closed in $X$.
\end{axiom}
-\begin{lemma}\label{urysohn_set_in_between}
+\begin{lemma}\label{urysohnone_urysohn_set_in_between}
Let $X$ be a urysohn space.
Suppose $A,B \in \closeds{X}$.
Suppose $A \subset B$.
@@ -284,7 +284,7 @@ The first tept will be a formalisation of chain constructions.
\end{proof}
-\begin{proposition}\label{urysohnchain_induction_begin}
+\begin{proposition}\label{urysohnone_urysohnchain_induction_begin}
Let $X$ be a urysohn space.
Suppose $A,B \in \closeds{X}$.
Suppose $A \inter B$ is empty.
@@ -347,7 +347,7 @@ The first tept will be a formalisation of chain constructions.
\end{proof}
-\begin{proposition}\label{urysohnchain_induction_begin_step_two}
+\begin{proposition}\label{urysohnone_urysohnchain_induction_begin_step_two}
Let $X$ be a urysohn space.
Suppose $A,B \in \closeds{X}$.
Suppose $A \inter B$ is empty.
@@ -364,7 +364,7 @@ The first tept will be a formalisation of chain constructions.
-\begin{proposition}\label{t_four_propositon}
+\begin{proposition}\label{urysohnone_t_four_propositon}
Let $X$ be a urysohn space.
Then for all $A,B \subseteq X$ such that $\closure{A}{X} \subseteq \interior{B}{X}$
we have there exists $C \subseteq X$ such that
@@ -376,7 +376,7 @@ The first tept will be a formalisation of chain constructions.
-\begin{proposition}\label{urysohnchain_induction_step_existence}
+\begin{proposition}\label{urysohnone_urysohnchain_induction_step_existence}
Let $X$ be a urysohn space.
Suppose $U$ is a urysohnchain in $X$.
Then there exist $U'$ such that $U'$ is a refinmant of $U$ and $U'$ is a urysohnchain in $X$.
@@ -390,7 +390,7 @@ The first tept will be a formalisation of chain constructions.
% such that $\closure{\indexx[U](n)}{X} \subseteq \interior{C}{X} \subseteq \closure{C}{X} \subseteq \interior{\indexx[U](n+1)}{X}$.
- %\begin{definition}\label{refinmant}
+ %\begin{definition}\label{urysohnone_refinmant}
% $C'$ is a refinmant of $C$ iff for all $x \in C$ we have $x \in C'$ and
% for all $y \in C$ such that $y \subset x$
% we have there exist $c \in C'$ such that $y \subset c \subset x$
@@ -404,7 +404,7 @@ The first tept will be a formalisation of chain constructions.
-\begin{proposition}\label{existence_of_staircase_function}
+\begin{proposition}\label{urysohnone_existence_of_staircase_function}
Let $X$ be a urysohn space.
Suppose $U$ is a urysohnchain in $X$ and $U$ has cardinality $k$.
Suppose $k \neq \zero$.
@@ -416,7 +416,7 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{abbreviation}\label{refinment_abbreviation}
+\begin{abbreviation}\label{urysohnone_refinment_abbreviation}
$x \refine y$ iff $x$ is a refinmant of $y$.
\end{abbreviation}
@@ -424,27 +424,27 @@ The first tept will be a formalisation of chain constructions.
-\begin{abbreviation}\label{sequence_of_functions}
+\begin{abbreviation}\label{urysohnone_sequence_of_functions}
$f$ is a sequence of functions iff $f$ is a sequence
and for all $g \in \carrier[f]$ we have $g$ is a function.
\end{abbreviation}
-\begin{abbreviation}\label{sequence_in_reals}
+\begin{abbreviation}\label{urysohnone_sequence_in_reals}
$s$ is a sequence of real numbers iff $s$ is a sequence
and for all $r \in \carrier[s]$ we have $r \in \reals$.
\end{abbreviation}
-\begin{axiom}\label{abs_behavior1}
+\begin{axiom}\label{urysohnone_abs_behavior1}
If $x \geq \zero$ then $\abs{x} = x$.
\end{axiom}
-\begin{axiom}\label{abs_behavior2}
+\begin{axiom}\label{urysohnone_abs_behavior2}
If $x < \zero$ then $\abs{x} = \neg{x}$.
\end{axiom}
-\begin{abbreviation}\label{converge}
+\begin{abbreviation}\label{urysohnone_converge}
$s$ converges iff $s$ is a sequence of real numbers
and $\indexxset[s]$ is infinite
and for all $\epsilon \in \reals$ such that $\epsilon > \zero$ we have
@@ -454,7 +454,7 @@ The first tept will be a formalisation of chain constructions.
\end{abbreviation}
-\begin{definition}\label{limit_of_sequence}
+\begin{definition}\label{urysohnone_limit_of_sequence}
$x$ is the limit of $s$ iff $s$ is a sequence of real numbers
and $x \in \reals$ and
for all $\epsilon \in \reals$ such that $\epsilon > \zero$
@@ -463,7 +463,7 @@ The first tept will be a formalisation of chain constructions.
we have $\abs{x - \indexx[s](n)} < \epsilon$.
\end{definition}
-\begin{proposition}\label{existence_of_limit}
+\begin{proposition}\label{urysohnone_existence_of_limit}
Let $s$ be a sequence of real numbers.
Then $s$ converges iff there exist $x \in \reals$
such that $x$ is the limit of $s$.
@@ -472,22 +472,22 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{definition}\label{limit_sequence}
+\begin{definition}\label{urysohnone_limit_sequence}
$x$ is the limit sequence of $f$ iff
$x$ is a sequence and $\indexxset[x] = \dom{f}$ and
for all $n \in \indexxset[x]$ we have
$\indexx[x](n) = f(n)$.
\end{definition}
-\begin{definition}\label{realsminus}
+\begin{definition}\label{urysohnone_realsminus}
$\realsminus = \{r \in \reals \mid r < \zero\}$.
\end{definition}
-\begin{abbreviation}\label{realsplus}
+\begin{abbreviation}\label{urysohnone_realsplus}
$\realsplus = \reals \setminus \realsminus$.
\end{abbreviation}
-\begin{proposition}\label{intervalclosed_subseteq_reals}
+\begin{proposition}\label{urysohnone_intervalclosed_subseteq_reals}
Suppose $a,b \in \reals$.
Suppose $a < b$.
Then $\intervalclosed{a}{b} \subseteq \reals$.
@@ -495,7 +495,7 @@ The first tept will be a formalisation of chain constructions.
-\begin{lemma}\label{fraction1}
+\begin{lemma}\label{urysohnone_fraction1}
Let $x \in \reals$.
Then for all $y \in \reals$ such that $x \neq y$ we have there exists $r \in \rationals$ such that $y < r < x$ or $x < r < y$.
\end{lemma}
@@ -503,7 +503,7 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{lemma}\label{frection2}
+\begin{lemma}\label{urysohnone_frection2}
Suppose $a,b \in \reals$.
Suppose $a < b$.
Then $\intervalopen{a}{b}$ is infinite.
@@ -512,7 +512,7 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{lemma}\label{frection3}
+\begin{lemma}\label{urysohnone_frection3}
Suppose $a \in \reals$.
Suppose $a < \zero$.
Then there exist $N \in \naturals$ such that for all $N' \in \naturals$ such that $N' > N$ we have $\zero < \rfrac{1}{\pot(N')} < a$.
@@ -521,7 +521,7 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{proposition}\label{fraction4}
+\begin{proposition}\label{urysohnone_fraction4}
Suppose $a,b,\epsilon \in \reals$.
Suppose $\epsilon > \zero$.
$\abs{a - b} < \epsilon$ iff $b \in \intervalopen{(a - \epsilon)}{(a + \epsilon)}$.
@@ -530,7 +530,7 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{proposition}\label{fraction5}
+\begin{proposition}\label{urysohnone_fraction5}
Suppose $a,b,\epsilon \in \reals$.
Suppose $\epsilon > \zero$.
$b \in \intervalopen{(a - \epsilon)}{(a + \epsilon)}$ iff $a \in \intervalopen{(b - \epsilon)}{(b + \epsilon)}$.
@@ -539,17 +539,17 @@ The first tept will be a formalisation of chain constructions.
Omitted.
\end{proof}
-\begin{proposition}\label{fraction6}
+\begin{proposition}\label{urysohnone_fraction6}
Suppose $a,\epsilon \in \reals$.
Suppose $\epsilon > \zero$.
$\intervalopen{(a - \epsilon)}{(a + \epsilon)} = \{r \in \reals \mid (a - \epsilon) < r < (a + \epsilon)\} $.
\end{proposition}
-\begin{abbreviation}\label{epsilonball}
+\begin{abbreviation}\label{urysohnone_epsilonball}
$\epsBall{a}{\epsilon} = \intervalopen{(a - \epsilon)}{(a + \epsilon)}$.
\end{abbreviation}
-\begin{proposition}\label{fraction7}
+\begin{proposition}\label{urysohnone_fraction7}
Suppose $a,\epsilon \in \reals$.
Suppose $\epsilon > \zero$.
Then there exist $b \in \rationals$ such that $b \in \epsBall{a}{\epsilon}$.
@@ -561,11 +561,11 @@ The first tept will be a formalisation of chain constructions.
-%\begin{definition}\label{sequencetwo}
+%\begin{definition}\label{urysohnone_sequencetwo}
% $Z$ is a sequencetwo iff $Z = (N,f,B)$ and $N \subseteq \naturals$ and $f$ is a bijection from $N$ to $B$.
%\end{definition}
%
-%\begin{proposition}\label{sequence_existence}
+%\begin{proposition}\label{urysohnone_sequence_existence}
% Suppose $N \subseteq \naturals$.
% Suppose $M \subseteq \naturals$.
% Suppose $N = M$.
@@ -586,7 +586,7 @@ The first tept will be a formalisation of chain constructions.
-\begin{theorem}\label{urysohn}
+\begin{theorem}\label{urysohnone_urysohn1}
Let $X$ be a urysohn space.
Suppose $A,B \in \closeds{X}$.
Suppose $A \inter B$ is empty.
@@ -599,7 +599,7 @@ The first tept will be a formalisation of chain constructions.
There exist $\eta$ such that $\carrier[\eta] = \{A, (\carrier[X] \setminus B)\}$
and $\indexxset[\eta] = \{\zero, 1\}$
and $\indexx[\eta](\zero) = A$
- and $\indexx[\eta](1) = (\carrier[X] \setminus B)$ by \cref{urysohnchain_induction_begin}.
+ and $\indexx[\eta](1) = (\carrier[X] \setminus B)$ by \cref{urysohnone_urysohnchain_induction_begin}.
We show that there exist $\zeta$ such that $\zeta$ is a sequence
and $\indexxset[\zeta] = \naturals$
@@ -919,6 +919,6 @@ The first tept will be a formalisation of chain constructions.
% \end{subproof}
\end{proof}
%
-%\begin{theorem}\label{safe}
+%\begin{theorem}\label{urysohnone_safe}
% Contradiction.
%\end{theorem}