Algebras of reduced $E$-Fountain semigroups and the generalized ample identity II (2209.07112v3)

Abstract: We study the generalized right ample identity, introduced by the author in a previous paper. Let $S$ be a reduced $E$-Fountain semigroup which satisfies the congruence condition. We can associate with $S$ a small category $\mathcal{C}(S)$ whose set of objects is identified with the set $E$ of idempotents and its morphisms correspond to elements of $S$. We prove that $S$ satisfies the generalized right ample identity if and only if every element of $S$ induces a homomorphism of left $S$-actions between certain classes of generalized Green's relations. In this case, we interpret the associated category $\mathcal{C}(S)$ as a discrete form of a Peirce decomposition of the semigroup algebra. We also give some natural examples of semigroups satisfying this identity.