A commutative semigroup S is subarchimedean if there exists z ∈ S such that for any a ∈ S, there are n ＞ 0 and x ∈ S s......

In his paper “On quasi-separative ‘semigroup’s’”, Krasilnikova, Yu. I. and Novikov, B. V. have studied congruences ......

In [1], a new consequence of the (restricted) wreath product for arbitrary monoids A and B with an underlying set . Let ......