From 14cc41cea592da7c342275073d66d2d6f7617ccc Mon Sep 17 00:00:00 2001 From: Josia Pietsch Date: Thu, 18 Jan 2024 17:17:27 +0100 Subject: [PATCH] some small changes --- inputs/lecture_09.tex | 1 + inputs/lecture_10.tex | 11 ++++++----- inputs/lecture_11.tex | 4 ++-- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/inputs/lecture_09.tex b/inputs/lecture_09.tex index ea1c2f6..c5f67d5 100644 --- a/inputs/lecture_09.tex +++ b/inputs/lecture_09.tex @@ -40,6 +40,7 @@ We will see that not every analytic set is Borel. $f$ is continuous by the weaker assertion of $f$ being Borel. \todo{Copy exercise from sheet 5} + % TODO WHY? \end{remark} \begin{theorem} diff --git a/inputs/lecture_10.tex b/inputs/lecture_10.tex index d6191dc..a8fb5ea 100644 --- a/inputs/lecture_10.tex +++ b/inputs/lecture_10.tex @@ -1,5 +1,6 @@ +\subsection{The Lusin Separation Theorem} + \lecture{10}{2023-11-17}{} -\todo{Start a new subsection here?} \begin{theorem}[\vocab{Lusin separation theorem}] \yalabel{Lusin Separation Theorem}{Lusin Separation}{thm:lusinseparation} Let $X$ be Polish and $A,B \subseteq X$ disjoint analytic. @@ -55,7 +56,7 @@ we need the following definition: such that $A \cap B = \emptyset$ Then there are continuous surjections $f\colon \cN \twoheadrightarrow A \subseteq X$ - and $g\colon \twoheadrightarrow B \subseteq X$. + and $g\colon \cN \twoheadrightarrow B \subseteq X$. Write $A_s \coloneqq f(\cN_s)$ and $B_s \coloneqq g(\cN_s)$. Note that $A_s = \bigcup_m A_{s\concat m}$ @@ -105,8 +106,8 @@ we need the following definition: Then $f(A)$ is Borel. \end{theorem} \begin{refproof}{thm:lusinsouslin} - W.l.o.g.~suppose that $f$ is continuous - $A$ is closed,\footnote{We might even assume that $A$ is clopen, but we only need closed.} + W.l.o.g.~suppose that $f$ is continuous, + $A$ is closed\footnote{We might even assume that $A$ is clopen, but we only need closed.} and $X = \cN$ by \yaref{thm:bairetopolish}: @@ -139,7 +140,7 @@ we need the following definition: \end{itemize} The second point follows from injectivity of $f$ and the fact that $\cN_{s \concat n} \cap \cN_{s\concat n'} = \emptyset$. - In particular, the $(B_s)$ for a Lusin scheme. + In particular, the $(B_s)$ form a Lusin scheme. Note that $f(A) = \bigcup_{s \in \omega^k} B_s$ for every $k <\omega$, diff --git a/inputs/lecture_11.tex b/inputs/lecture_11.tex index 60a9e6f..641f969 100644 --- a/inputs/lecture_11.tex +++ b/inputs/lecture_11.tex @@ -118,7 +118,7 @@ Hence \yaref{thm:bsb} can be applied. \end{proof} -\subsection{Projective Hierarchy} +\subsection{The Projective Hierarchy} % https://q.uiver.app/#q=WzAsNixbMCwxLCJcXERlbHRhXjFfMShYKSJdLFsxLDAsIlxcU2lnbWFeMV8xKFgpIl0sWzEsMiwiXFxQaV4xXzEoWCkiXSxbMiwxLCJcXERlbHRhXjFfMihYKSJdLFszLDAsIlxcU2lnbWFeMV8yKFgpIl0sWzMsMiwiXFxQaV4xXzIoWCkiXSxbMCwxLCJcXHN1YnNldGVxIiwwLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XSxbMCwyLCJcXHN1YnNldGVxIiwyLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XSxbMiwzLCJcXHN1YnNldGVxIiwyLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XSxbMSwzLCJcXHN1YnNldGVxIiwwLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XSxbMyw0LCJcXHN1YnNldGVxIiwwLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XSxbMyw1LCJcXHN1YnNldGVxIiwwLHsic3R5bGUiOnsidGFpbCI6eyJuYW1lIjoiaG9vayIsInNpZGUiOiJ0b3AifX19XV0= @@ -151,7 +151,7 @@ We will not proof this in this lecture. -\subsection{Trees} % TODO section? +\subsection{Ill-Founded Trees} Recall that a \vocab{tree} on $\N$ is a subset of