TeX source:

\text{CNOT}\frac{1}{\sqrt{2}}\begin{bmatrix}1 & 0 & -1 & 0\end{bmatrix}^\top = \frac{1}{\sqrt{2}}\begin{bmatrix}1 & 0 & 0 & -1\end{bmatrix}^\top = \frac{1}{\sqrt{2}}(|00\rangle - |11\rangle).