Strongly E-reflexive inverse semigroups
Liam O’Carroll · Proceedings of the Edinburgh Mathematical Society · 1977
LetSbe an inverse semigroup with semilattice of idempotentsE. We denote by σ the minimum group congruence onS(6), and by τ the maximum idempotent-determined congruence onS(2). (Recall that the congruence η onSis calledidempotent-determinedif (e,x)∈ η ande∈Eimply thatx∈E.) In general τ ⊆ σ.