diff options
Diffstat (limited to 'library/topology')
| -rw-r--r-- | library/topology/urysohn.tex | 82 |
1 files changed, 42 insertions, 40 deletions
diff --git a/library/topology/urysohn.tex b/library/topology/urysohn.tex index d8b1e14..414043f 100644 --- a/library/topology/urysohn.tex +++ b/library/topology/urysohn.tex @@ -526,6 +526,11 @@ The first tept will be a formalisation of chain constructions. Omitted. \end{subproof} + We show that for all $n \in \naturals$ for all $x \in \carrier[X]$ we have $\apply{\gamma(n)}{x} \in \intervalclosed{\zero}{1}$. + \begin{subproof} + Omitted. + \end{subproof} + We show that there exist $g$ such that @@ -535,18 +540,7 @@ The first tept will be a formalisation of chain constructions. there exist $N \in \naturals$ such that for all $N' \in \naturals$ such that $N' > N$ we have $\abs{\apply{\gamma(n)}{x} - k} < \epsilon$ and $g(x)= k$. - \begin{subproof} - - %Let $G(x) = \{k \in \carrier[X] \mid \forall \epsilon \in \realsplus. \exists N \in \naturals. \forall N' \in \naturals. (N' > N) \land (\abs{\apply{\gamma(n)}{x} - k} < \epsilon)\}$ for $x \in \carrier[X]$. -% - %We show that for all $x \in \carrier[X]$ we have $G(x)$ has cardinality $1$. - %\begin{subproof} - % Omitted. - %\end{subproof} -% - %Let $H(x) = \unions{G(x)}$ for $x \in \carrier[X]$. - %For all $x \in \carrier[X]$ we have $\{H(x)\} = G(x)$. - + \begin{subproof} We show that for all $x \in \carrier[X]$ we have there exist $k \in \reals$ such that for all $\epsilon \in \reals$ such that $\epsilon > \zero$ we have @@ -554,10 +548,9 @@ The first tept will be a formalisation of chain constructions. for all $N' \in \naturals$ such that $N' > N$ we have $\abs{\apply{\gamma(n)}{x} - k} < \epsilon$. \begin{subproof} - Omitted. + Fix $x \in \carrier[X]$. + Follows by \cref{two_in_naturals,function_apply_default,reals_axiom_zero_in_reals,dom_emptyset,notin_emptyset,funs_type_apply,neg,minus,abs_behavior1}. \end{subproof} - - \end{subproof} @@ -581,44 +574,53 @@ The first tept will be a formalisation of chain constructions. %\begin{subproof} % Omitted. %\end{subproof} + + Let $G(x) = g(x)$ for $x \in \carrier[X]$. + We have $\dom{G} = \carrier[X]$. - - We show that $F \in \funs{\carrier[X]}{\intervalclosed{\zero}{1}}$. - \begin{subproof} + %For all $x \in \carrier[X]$ for all $n \in \naturals$ we have $g(x) \leq \apply{\gamma(n)}{x}$. + + We show that for all $x \in \dom{G}$ we have $G(x) \in \reals$. + \begin{subproof} + Fix $x \in \dom{G}$. + It suffices to show that $g(x) \in \reals$. + + %There exist $k \in \reals$ such that for all $\epsilon \in \reals$ such that $\epsilon > \zero$ we have there exist $N \in \naturals$ such that for all $N' \in \naturals$ such that $N' > N$ we have $\abs{\apply{\gamma(n)}{x} - k} < \epsilon$ and $g(x)= k$. + + + + \end{subproof} + + We show that for all $x \in \dom{G}$ we have $\zero \leq G(x) \leq 1$. + \begin{subproof} Omitted. - - %It suffices to show that $\dom{F} = \carrier[X]$ and - %$F \in \rels{\carrier[X]}{\intervalclosed{\zero}{1}}$ and $F$ is right-unique. - % - %We show that $F \in \rels{\carrier[X]}{\intervalclosed{\zero}{1}}$. - %\begin{subproof} - % It suffices to show that $F \in \pow{\carrier[X] \times \intervalclosed{\zero}{1}}$. - % It suffices to show that for all $w \in F$ we have $w \in (\carrier[X] \times \intervalclosed{\zero}{1})$. -% - % Fix $w \in F$. -% - % %Take $x$ such that there exist $k \in \intervalclosed{\zero}{1}$ such that $w = (x,k)$. -% -% - %\end{subproof} - % -% -% - %Trivial. \end{subproof} - We show that $F(A) = \zero$. + + We show that $G \in \funs{\carrier[X]}{\intervalclosed{\zero}{1}}$. + \begin{subproof} + It suffices to show that $\ran{G} \subseteq \intervalclosed{\zero}{1}$ by \cref{fun_ran_iff,funs_intro,funs_weaken_codom}. + It suffices to show that for all $x \in \dom{G}$ we have $G(x) \in \intervalclosed{\zero}{1}$. + Fix $x \in \dom{G}$. + Then $x \in \carrier[X]$. + $g(x) = G(x)$. + We have $G(x) \in \reals$. + $\zero \leq G(x) \leq 1$. + We have $G(x) \in \intervalclosed{\zero}{1}$ . + \end{subproof} + + We show that $G(A) = \zero$. \begin{subproof} Omitted. \end{subproof} - We show that $F(B) = 1$. + We show that $G(B) = 1$. \begin{subproof} Omitted. \end{subproof} - We show that $F$ is continuous. + We show that $G$ is continuous. \begin{subproof} Omitted. \end{subproof} |
