\KwIn{ $ A \in \mathbb{R}^{N \times N}$, $b \in \mathbb{R}^N$,
and initial guess $x_0 \in \mathbb{R}^N$}
\KwOut{ $x \in \mathbb{R}^N$: $\| b - A x\|_2 < tol$}
\KwIn{ $ A \in \mathbb{R}^{N \times N}$, $b \in \mathbb{R}^N$,
and initial guess $x_0 \in \mathbb{R}^N$}
\KwOut{ $x \in \mathbb{R}^N$: $\| b - A x\|_2 < tol$}