\(R_{\text {Symmetric}} = \begin{pmatrix} * &{} \alpha &{} \beta &{} \gamma \\ \eta &{} * &{} \delta &{} \epsilon \\ \epsilon &{} \delta &{} * &{} \eta \\ \gamma &{} \beta &{} \alpha &{} * \end{pmatrix}, R_{\text {GTR}}= \begin{pmatrix} * &{} \pi _A \alpha &{} \pi _A \beta &{} \pi _A \gamma \\ \pi _C \alpha &{} * &{} \pi _C \delta &{} \pi _C \epsilon \\ \pi _G \beta &{} \pi _G \delta &{} * &{} \pi _G \eta \\ \pi _T \gamma &{} \pi _T \epsilon &{} \pi _T \eta &{} * \end{pmatrix}\) |