> [!NOTE] Definition (Two-row Notation) > Let $n\in\mathbb{N}^{+}$ and $\rho:\mathbb{N}^{+}_{\leq n}\to \mathbb{N}^{+}_{\leq n}$ be a [[Permutation of Finite Degree|permutation of n letters]], then $\rho$ is denoted using two-row notation as $\begin{pmatrix} 1 & 2 & \dots & n \\ \rho(1) & \rho(2) & \dots & \rho(n) \end{pmatrix}$