Stable Auslander–Reiten quiver
= Stable Auslander–Reiten quiver
{title2=$\Gamma_s(A)$}
For a self-injective finite-dimensional <algebra>, remove the projective vertices from its <Auslander–Reiten quiver>. The resulting stable quiver has vertices the nonprojective indecomposable modules. Its translation sends the end term of an almost-split exact sequence to its start term. In particular a quiver of shape $\mathbb ZA_s/\langle\tau^e\rangle$ has $es$ vertices.