Consider the quiver $1 \overset{\alpha}{\underset{\alpha'}{\leftleftarrows}} 2$. I am trying to find the form of the Auslander–Reiten quiver. So I got :
$P(1)= \begin{matrix} 1 \end{matrix}$, $P(2) =\begin{matrix} 2 &\\ 1 & 1 \end{matrix}$, $I(1) =\begin{matrix} 2 & 2\\ 1 & \end{matrix}$, $I(2)= \begin{matrix} 2 \end{matrix}$, $S(1)=1$, $S(2)=2$. I am just curious about how the Auslander–Reiten quiver looks like.