On the embedding of semigroups into finitely generated commutative semigroups
摘要
We describe varieties of commutative semigroups in which free countable semigroups embed into finitely generated commutative semigroups. We also refute two natural embeddability conjectures; in particular, we show that the finiteness of the number of Archimedean components is not necessary for the embeddability into finitely generated commutative semigroups. We establish a criterion for the embeddability of cancellative semigroups into finitely generated commutative semigroups.