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-rw-r--r--library/topology/urysohn2.tex30
1 files changed, 22 insertions, 8 deletions
diff --git a/library/topology/urysohn2.tex b/library/topology/urysohn2.tex
index 40a3615..71de210 100644
--- a/library/topology/urysohn2.tex
+++ b/library/topology/urysohn2.tex
@@ -68,18 +68,32 @@
Let $H = \carrier[X] \setminus B$.
Let $P = \{x \in \pow{X} \mid x = A \lor x = H \lor (x \in \pow{X} \land (\closure{A}{X} \subseteq \interior{U}{X} \subseteq \closure{U}{X} \subseteq \interior{H}{X}))\}$.
+ Let $\eta = \carrier[X]$.
-
-
- Define $f : X \to \reals$ such that $f(x) = $
+
+ % Provable
+ % vvv
+ Define $F : \eta \to \reals$ such that $F(x) =$
\begin{cases}
- &(x + k) &\text{if} x \in X \land k \in \naturals
- & x &\text{if} x \neq \zero
- & \zero & \text{if} x = \zero
- % & x ,x \in X <- will result in technicly ambigus parse
+ & \zero &\text{if} x \in A\\
+ & \rfrac{1}{1+1} &\text{if} x \in (\carrier[X] \setminus (A \union B))\\
+ & 1 &\text{if} x \in B
\end{cases}
-
+ %Define $f : \naturals \to \pow{P}$ such that $f(x)=$
+ %\begin{cases}
+ % & \emptyset & \text{if} x = \zero \\
+ % & \{A, H\} & \text{if} x = 1 \\
+ % & G & \text{if} x \in (\naturals \setminus \{1, \zero\}) \land G = \{g \in \pow{P} \mid g \in f(n-1) \lor (g \notin f(n-1) \land g \in P) \}
+ %\end{cases}
+
+ Let $D = \{d \mid d \in \rationals \mid \zero \leq d \leq 1\}$.
+ Take $R$ such that for all $q \in D$ we have for all $S \in P$ we have $q \mathrel{R} S$ iff
+ $q = \zero \land S = A$ or $q = 1 \land S = H$ or
+ for all $q_1, q_2, S_1, S_2$
+ such that $q_1 \leq q \leq q_2$ and $q_1 \mathrel{R} S_1$ and $q_2 \mathrel{R} S_2$
+ we have $\closure{S_1}{X} \subseteq \interior{S}{X} \subseteq \closure{S}{X} \subseteq \interior{S_2}{X}$
+ and $q \mathrel{R} S$.
Trivial.