Compatible additions on a six-element commutative semigroup: equational bases and subvariety lattices

Lili Wang, Jinjing Wu, Aifa Wang

Let $M$ be the six-element commutative semigroup occurring as the common multiplicative reduct of the semirings $S{R}_6$ and $T{R}_6$. The closing paragraph of Shao, Ren, and Gao~\cite…