diff --git a/inputs/lecture_12.tex b/inputs/lecture_12.tex index feb3e2e..4f62638 100644 --- a/inputs/lecture_12.tex +++ b/inputs/lecture_12.tex @@ -59,12 +59,11 @@ Take $A \in \Sigma^1_1(X) \setminus \cB(X)$% \footnote{e.g.~\yaref{thm:universals11}} and $f\colon X \to Y$ Borel. - But then we get that $f^{-1}(B)$ is Borel $\lightnig$. + But then we get that $f^{-1}(B)$ is Borel $\lightning$. }{.} \end{itemize} \end{observe} -% TODO ANKI-MARKER \begin{theorem} \label{thm:lec12:1} Suppose that $A \subseteq \cN$ is analytic. diff --git a/inputs/lecture_13.tex b/inputs/lecture_13.tex index ab38e1e..5d9cd9c 100644 --- a/inputs/lecture_13.tex +++ b/inputs/lecture_13.tex @@ -1,11 +1,12 @@ \lecture{13}{2023-11-08}{} - +\gist{% % Recap $\LO = \{x \in 2^{\N\times \N} : x \text{ is a linear order}\} $. $\LO \subseteq 2^{\N \times \N}$ is closed and $\WO = \{x \in \LO: x \text{ is a wellordering}\} $ is coanalytic in $\LO$. % End Recap +}{} Another way to code linear orders: @@ -32,6 +33,8 @@ with $(f^{-1}(\{1\}), <)$. and $[\alpha_i, \alpha_{i+1})$ to $(i,i+1)$. \end{proof} +% TODO ANKI-MARKER + \begin{definition}[\vocab{Kleene-Brouwer ordering}] Let $(A,<)$ be a linear order and $A$ countable. We define the linear order $<_{KB}$ on $A^{<\N}$