The Gorenstein property depends upon characteristic for affine semigroup rings (Q582338)

Let S be an affine semigroup, i.e. a finitely generated submonoid of \({\mathbb{N}}^ n\). After developing a certain theory on affine semigroup rings k[S], Trung and the author showed that the Cohen-Macaulayness and the Buchsbaumness of such rings are dependent upon char(k). This property was well-known in the case of Stanley-Reisner rings. In this note it is shown that also the Gorenstein property of k[S] is dependent upon char(k).