Combinatorial results for order-preserving and order-decreasing transformations


AYIK G. , Ayik H., KOC M.

TURKISH JOURNAL OF MATHEMATICS, cilt.35, ss.617-625, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 35 Konu: 4
  • Basım Tarihi: 2011
  • Doi Numarası: 10.3906/mat-1010-432
  • Dergi Adı: TURKISH JOURNAL OF MATHEMATICS
  • Sayfa Sayıları: ss.617-625

Özet

Let O(n) and C(n) be the semigroup of all order-preserving transformations and of all order-preserving and order-decreasing transformations on the finite set X(n) = {1,2, ..., n}, respectively. Let Fix(alpha) = {x is an element of X(n) : x alpha = x} for any transformation alpha. In this paper; for any Y subset of X(n), we find the cardinalities of the sets O(n,Y) = {alpha is an element of O(n) : Fix(alpha) = Y} and C(n,Y) = {alpha is an element of C(n) : Fix(alpha) = Y}. Moreover; we find the numbers of transformations of O(n) and C(n) with r fixed points.