diff --git a/inputs/lecture_07.tex b/inputs/lecture_07.tex index bae467d..687e009 100644 --- a/inputs/lecture_07.tex +++ b/inputs/lecture_07.tex @@ -144,8 +144,9 @@ \begin{proof} Consider $(F, \cT\defon{F})$ and $(X \setminus F, \cT\defon{X \setminus F})$. Both are Polish spaces. - Take the coproduct\footnote{topological sum} $F \oplus (X \setminus F)$ - of these spaces. + Take the coproduct% + \footnote{In the lecture, this was called the \vocab{topological sum}.} + $F \oplus (X \setminus F)$ of these spaces. This space is Polish, and the topology is generated by $\cT \cup \{F\}$, hence we do not get any new Borel sets. diff --git a/inputs/lecture_09.tex b/inputs/lecture_09.tex index c3a61ce..ea1c2f6 100644 --- a/inputs/lecture_09.tex +++ b/inputs/lecture_09.tex @@ -26,7 +26,7 @@ Let $X$ be a Polish space. A set $A \subseteq X$ is called \vocab{analytic} - if + iff \[ \exists Y \text{ Polish}.~\exists B \in \cB(Y).~ \exists \underbrace{f\colon Y \to X}_{\text{continuous}}.~