On free contents
Takayuki Tamura · Proceedings of the Japan Academy Series A Mathematical Sciences · 1968
An S-indecomposable semigroup is a semi- group which has no semilattiee-homomorphie image except a trivial one.We will call an S-indeeomposable semigroup 3-simple in the sense that a semigroup S is S-indeeomposable if and only if it has no prime ideal, that is, S has no ideal I suela that I:/: S arid S \ I is a sub- semigroup of S (el.[1]).