Let OPCTn (OCTn) denote the semigroup consisting of all orientation-preserving (order-preserving) full contraction mappings on the finite chain Xn = 1 < ··· < n, and let OPDCTn (ODCTn) denote the subsemigroup of OPCTn (OCTn) consisting of all order-decreasing transformations. The purpose of this paper is to determine the cardinalities of OPCTn, OPDCTn, N (ODCTn), and N (OPDCTn), and to identify generating sets of minimal size, thereby determining their ranks. Moreover, the number of idempotents of OPDCTn is determined.
AYIK et al. (Tue,) studied this question.