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@ -164,4 +164,4 @@ Note that open sets and meager sets have the Baire property.
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by the \yaref{thm:bct}.
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\end{itemize}
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\end{example}
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}
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}{}
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@ -95,7 +95,7 @@
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% Nwd set of positive measure.
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% TODO
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% remove open intervals such that their length does not add to 0
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%
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%
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%\end{example}
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\begin{theorem}[Baire Category theorem]
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@ -114,8 +114,8 @@
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\item The intersection of countable many
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open dense sets is dense.
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\end{enumerate}
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In this case $X$ is called a \vocab{Baire space}.
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\footnote{see \yaref{s5e1}}
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In this case $X$ is called a \vocab{Baire space}.%
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\footnote{cf.~\yaref{s5e1}}
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\end{theoremdef}
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\begin{proof}
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\todo{Proof (short)}
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@ -127,12 +127,11 @@
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We have that
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\[
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\emptyset = \bigcap_{n} (X \setminus \overline{A_n})
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\]
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\]
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is dense by (iii).
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This proof can be adapted to other open sets $X$.
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\end{proof}
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\begin{notation}
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Let $X ,Y$ be topological spaces,
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$A \subseteq X \times Y$
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@ -141,12 +140,12 @@
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Let
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\[
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A_x \coloneqq \{y \in Y : (x,y) \in A\}
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\]
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A_x \coloneqq \{y \in Y : (x,y) \in A\}
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\]
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and
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\[
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A^y \coloneqq \{x \in X : (x,y) \in A\} .
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\]
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\]
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\end{notation}
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The following similar to Fubini,
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@ -175,9 +175,10 @@ By Zorn's lemma, this will follow from
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\end{IEEEeqnarray*}
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The topology induced by the metric
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is given by basic open subsets\footnote{see Exercise Sheet 9% TODO REF
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}
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$[U_0; U_1,\ldots, U_n]$, $U_0,\ldots, U_n \overset{\text{open}}{\subseteq} X$,
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is given by basic open subsets\footnote{cf.~\yaref{s9e2}}
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of the form
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$[U_0; U_1,\ldots, U_n]$,
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for $U_0,\ldots, U_n \overset{\text{open}}{\subseteq} X$,
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where
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\[
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[U_0; U_1,\ldots,U_n] \coloneqq
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@ -188,8 +189,8 @@ By Zorn's lemma, this will follow from
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We want to view flows as a metric space.
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For a fixed compact metric space $X$,
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we can view the flows $(X,\Z)$ as a subset of $\cC(X,X)$.
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Note that $\cC(X,X)$ is Polish.
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Then the minimal flows on $X$ are a Borel subset of $\cC(X,X)$.
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Note that $\cC(X,X)$ is Polish.\footnote{cf.~\yaref{s1e4}}
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Then the minimal flows on $X$ are a Borel subset of $\cC(X,X)$.\footnote{Exercise} % TODO
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However we do not want to consider only flows on a fixed space $X$,
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but we want to look all flows at the same time.
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