diff --git a/docs/Matrix.md b/docs/Matrix.md
index 8ed25f9..eccbc64 100644
--- a/docs/Matrix.md
+++ b/docs/Matrix.md
@@ -165,7 +165,7 @@ e^{-i\frac \phi 2} & 0\\
 1 & 0 & 0 & 0\\
 0 & 1 & 0 & 0\\
 0 & 0 & 0 & 1\\
-0 & 0 & 1 & 0\\
+0 & 0 & 1 & 0
 \end{pmatrix}
 ```
 
@@ -178,6 +178,19 @@ e^{-i\frac \phi 2} & 0\\
 1 & 0 & 0 & 0\\
 0 & 0 & 1 & 0\\
 0 & 1 & 0 & 0\\
-0 & 0 & 0 & 0\\
+0 & 0 & 0 & 0
+\end{pmatrix}
+```
+
+- ```Cu(u: Matrix) -> Matrix```
+
+  returns the matrix
+
+```math
+\begin{pmatrix}
+1 & 0 & 0 & 0\\
+0 & 1 & 0 & 0\\
+0 & 0 & u_{00} & u_{01}\\
+0 & 0 & u_{10} & u_{11}\\
 \end{pmatrix}
 ```