HACETTEPE JOURNAL OF MATHEMATICS AND STATISTICS, cilt.49, sa.6, ss.1988-1996, 2020 (SCI-Expanded)
Let T-n be the (full) transformation semigroup, and let OCTn and ORCTn be its subsemigroups of isotone contractions and of monotone contractions on a finite chain X-n = {1, ..., n} under its natural order, respectively. In this study, we obtain the ranks of the ideals OCTn,r = {alpha is an element of OCTn : vertical bar im (alpha)vertical bar <= r} and ORCTn,r =vertical bar im (alpha)vertical bar <= r} for 1 <= r <= n - 1.