Abstract A transformation of an ordered set M is isotone mapping into . By a representation semigroup S by transformations we mean homomorphism the , i.e. (since semigroup) from preserving operations. We prove that this type leads to “action” on and so introduce notion left operand over Also notions operator pseudoorder between operands show concept pseudoorders plays important role in study ho...

We study the number of solutions of the general semigroup equation in one variable, X α = X β , as well as of the system of equations X 2 = X, Y 2 = Y, XY = Y X in H ≀ T n , the wreath product of an arbitrary finite group H with the full transformation semigroup T n on n letters. For these solution numbers, we provide explicit exact formulae, as well as asymptotic estimates. Our results concern...

Let c () be the collapse of full transformation semigroup, Tn. Then the general formula to calculate the number of collapsible elements, | tα-1| 2 is derived for all n 0, which is an extension of [1] (A.O. Adeniji and S.O. Makanjuola (2008), ‘On some combinatorial results of collapse and properties of height in full transformation semigroups,’ African Journal of Computing & ICT (Journal of the...

Goes to the advanced topics rather fast. Contains up-to-date proofs for free inverse semigroups, topics on biordered sets, Isbell's zigzags , and some combinatorics of transformation semigroups.] Fundamentals of semigroup theory, 1995. [Probably the best introduction. Contains more advanced material such as Isbell's zigzags , and the free inverse semi-groups]. G. Lallement, Semigroups and combi...

Let T x be the full transformation semigroup on the set X and let S be a subsemigroup of Tx. We may associate with S a digraph g(5) with X as set of vertices as follows: / —► / e g(<S) iff there exists a 6 S such that a(i) = /. Conversely, for a digraph C having certain properties we may assign a semigroup structure, S(G), to the underlying set of G. We are thus able to establish a "Galois corr...

Given a group G of permutations of a finite n-element set Xn and a transformation f of Xn, the G-closure 〈f : G〉 of f is the semigroup generated by all the conjugates of f by permutations in G. A semigroup S of transformations of Xn is G-normal if GS = G, where GS consists of all the permutations h of Xn such that h−1fh ∈ S for all f ∈ S. We may assume that Xn is a chain and we let POIn be the ...

Let $S$ be a semitopological semigroup. The $wap-$ compactification of semigroup S, is a compact semitopological semigroup with certain universal properties relative to the original semigroup, and the $Lmc-$ compactification of semigroup $S$ is a universal semigroup compactification of $S$, which are denoted by $S^{wap}$ and $S^{Lmc}$ respectively. In this paper, an internal construction of ...

in the present paper we give a partially negative answer to a conjecture of ghahramani, runde and willis. we also discuss the derivation problem for both foundation semigroup algebras and clifford semigroup algebras. in particular, we prove that if s is a topological clifford semigroup for which es is finite, then h1(m(s),m(s))={0}.

We develop the theory of transformation semigroups that have degree 2, is, act by partial functions on a finite set such inverse image points at most two elements. show graph fibers an action gives deep connection between semigroup and theory. It is known Krohn–Rhodes complexity 2 2. monoid continuous maps translational hull appropriate 0-simple semigroup. how group mapping can be considered as...

Denote by PSelf Ω (resp., Self Ω) the partial (resp., full) transformation monoid over a set Ω, and by SubV (resp., EndV ) the collection of all subspaces (resp., endomorphisms) of a vector space V . We prove various results that imply the following: (1) If cardΩ > 2, then Self Ω has a semigroup embedding into the dual of Self Γ iff card Γ > 2 . In particular, if Ω has at least two elements, th...