diff --git a/thesis/chapters/introduction_qc.tex b/thesis/chapters/introduction_qc.tex
index 8fa6373..583370c 100644
--- a/thesis/chapters/introduction_qc.tex
+++ b/thesis/chapters/introduction_qc.tex
@@ -91,7 +91,7 @@ The following notation\cite{dahlberg_ea2019} can be more handy when discussing m
 \end{equation}
 
 Where $i$ is the act-qbit, $j$ the control-qbit and $I_i$, $Z_i$ are the identity and Pauli $Z$ gate
-operating on qbit i.
+operating on qbit i. Note that $CX(i, j) = H(i) CZ(i, j) H(i)$ which will be important later.
 
 \subsection{Measurement}