diff --git a/inputs/lecture_17.tex b/inputs/lecture_17.tex
index 5fe9acb..cac776a 100644
--- a/inputs/lecture_17.tex
+++ b/inputs/lecture_17.tex
@@ -1,5 +1,4 @@
 \subsection{The Ellis semigroup}
-% TODO ANKI-MARKER
 \lecture{17}{2023-12-12}{The Ellis semigroup}
 
 Let $(X, d)$ be a compact metric space
@@ -75,7 +74,7 @@ Properties of $(X,T)$ translate to properties of $E(X,T)$:
         \]
     \end{claim}
     \begin{subproof}
-        \todo{Homework}
+        Cf.~\yaref{s11e1}
     \end{subproof}
 
     Let $g \in G$.
@@ -163,6 +162,8 @@ But it is interesting for other semigroups.
     \todo{The other direction is left as an easy exercise.}
 \end{proof}
 
+% TODO ANKI-MARKER
+
 Let $(X,T)$ be a flow.
 Then by Zorn's lemma, there exists $X_0 \subseteq X$
 such that $(X_0, T)$ is minimal.