400. That’s an error.

Your client has issued a malformed or illegal request.

• The parameter 'chl=\begin{bmatrix}2 & 3\\ 4 & 5\end{bmatrix} \begin{bmatrix}1 &2 \\ 6&7\end{bmatrix}=\begin{bmatrix}2 & 3\\ 4 & 5\end{bmatrix} \begin{bmatrix}1\\ 6\end{bmatrix}+\begin{bmatrix}2 & 3\\ 4 & 5\end{bmatrix} \begin{bmatrix}2\\ 7\end{bmatrix}' exceeds the maximum formula length of 200 characters.