Jörg Koppitz

On the semigroups of fence-decreasing and fence-preserving transformations on a finite fence

Abstract For a natural number n , a fence [ n ] = {1 ≺ 2 ≻ 3 ≺ 4 ≻ 5 ≺⋯ n } is a partial ordered set. A partial transformation α is called fence-decreasing if xα ⪯ x for all x in the domain of α , and fence-preserving if x ≺ y implies xα ⪯ yα for all x and y in the domain of α ....