Non-Specht variety generated by an involution semigroup of order five
Edmond W. H. Lee · Transactions of the Moscow Mathematical Society · 2021
The non-orthodox 0-simple semigroup $A_2$ of order five admits a unary operation under which it is an involution semigroup. It is known that $A_2$ generates a Specht variety of semigroups. In contrast, it is shown that as an involution semigroup, $A_2$ generates a non-Specht variety.