*-QUASIIDEALS IN INVOLUTION SEMIGROUPS

摘要

Let S be an involution semigroup Then every *-minimal *-quasiideal of S is a minimal *-quaslideal of S. Nevertheless, if S possesses a primitive idempotent e then the *-quasiideal dSe~* (e~* Se) is minimal if and only if it is a (von Neumann) regular *-subsemigroup. Furthermore, S *-simple if and only if it is simple Finally, if S has a minima: *-quasiideal then it has a completely simple kernel K and the minimal *-quasiideals of S are just the * maximal *-subgroups of K.