Bondarenko, V.; Tertychna, O.
(Algebra and Discrete Mathematics, 2012)
Let I be a finite set (without 0) and J a subset of I × I without diagonal elements. Let S(I, J) denotes the semigroup generated by e₀ = 0 and ei, i ∈ I, with the following relations: e²i = ei for any i ∈ I, eiej = 0 for ...