Let [Formula: see text] be a nonempty set and let the full transformation semigroup on text]. The main objective of this paper is to study subsemigroup defined by where fixed subset We describe regular elements in text], show that if only finite. characterize unit-regular prove Green’s relations also determine ideals investigate its kernel. This extends several results have appeared literature.

In this paper, a new  algorithm for computing secondary invariants of  invariant rings of monomial groups is presented. The main idea is to compute simultaneously a truncated SAGBI-G basis and the standard invariants of the ideal generated by the set of primary invariants.  The advantage of the presented algorithm lies in the fact that it is well-suited to complexity analysis and very easy to i...

We say that two unitary or orthogonal representations of a finitely generated group G are additive conjugates if they intertwined by an map, which need not be continuous. associate to each representation topological action is complete conjugacy invariant: the automorphisms on Bohr compactification underlying Hilbert space. Using this construction we show property having almost invariant vectors...

In this paper, we extend the domains of affirmation and negation operators, and more important, of triangular (semi)norms and (semi)conorms from the unit interval to bounded partially ordered sets. The fundamental properties of the original operators are proven to be conserved under this extension. This clearly shows that they are essentially based upon order-theoretic notions. Consequently, a ...