Let X n be a chain with n elements (n∈ ℕ), and let 𝒪𝒫 n be the monoid of all orientation-
preserving transformations of X n. In this article, for any nonempty subset Y of X n, we …

Let Xn={1, 2,..., n}. On a partial transformation α: Dom α⊆ Xn→ Im α⊆ Xn of Xn the following
parameters are defined: the breadth or width of α is| Dom α|, the collapse of α is c (α)=|∪ t∈ …

Let In be the symmetric inverse semigroup on Xn={1, 2,..., n} under composition of maps and
let DPn and ODPn be its subsemigroups of partial isometries and of order-preserving partial …

Let Xn={1, 2,⋯, n} and let α: Domα⊆ Xn→ Imα⊆ Xn be a (partial) transformation on Xn. On a
partial one-one mapping of Xn the following parameters are defined: the height of α is h (α) …

For n ∈ N n∈ N, let C _ n C n be the semigroup of all order-preserving and decreasing
transformations on X_ n={1, ..., n\} X n= 1,…, n, under its natural order, and let N (C _ n) N (C …

In this paper we give formulas for the number of elements of the monoids ORm× n of all full
transformations on a finite chain with mn elements that preserve a uniform m-partition and …

The set of discrete lattice paths from (0, 0) to (n, n) with North and East steps (ie words w ∈
{\, x, y\,\}^* such that| w| _ x=| w| _ y= n) has a canonical monoid structure inherited from the …

We characterize the monoid of endomorphisms of the semigroup of all oriented full
transformations of a finite chain, as well as the monoid of endomorphisms of the semigroup …

In this paper, we characterize the monoid of endomorphisms of the semigroup of all
monotone full transformations of a finite chain, as well as the monoids of endomorphisms of …

For n ∈ N n∈ N, let O_ n O n be the semigroup of all order-preserving transformations on
the finite chain X_ n={1, ..., n\} X n= 1,…, n, under its natural order. For any non-empty subset …