Abstract
Three results are obtained concerning the number of order preserving maps of an n-element partially ordered set to itself. We show that any such ordered set has at least 22n/3 order preserving maps (and 22 in the case of length one). Precise asymptotic estimates for the numbers of self-maps of crowns and fences are also obtained. In addition, lower bounds for many other infinite families are found and several precise problems are formulated.
Similar content being viewed by others
References
G. Birkhoff (1967) Lattice Theory (3rd ed), AMS, Providence.
R. Canfield and Richard Duke (1991) private communication.
J. Currie and T. Visentin (1991) The number of order preserving maps of fences and crowns, Order 8, 133–142.
W. Hoefding (1963). Probability inequalities for sums of bounded random variables, J. Amer. Stat. Ass. 58, 13–30.
W.-P. Liu, I. Rival, and N. Zaguia (1991) Automorphisms, isotone self-maps and cycle-free orders, preprint.
I. Rival and A. Rutkowski (1990) Does almost every isotone self-map have a fixed point? preprint.
D. G. Robinson (1991) Fence endomorphisms and lattice paths with diagonal steps, preprint.
J. Spencer (1987) Ten Lectures on the Probabilistic Method, SIAM, Philadelphia.
R. G. Stanton and D. D. Cowan (1970) Note on a “square” functional equation. SIAM Review 12, 277–279.
W. T. Trotter (1989) private communication.
Author information
Authors and Affiliations
Additional information
Communicated by N. Zaguia
Supported by ONR Contract N00014-85-K-0769.
Supported by NSF Grant DMS-9011850.
Supported by NSERC Grants 69-3378 and 69-0259.
Rights and permissions
About this article
Cite this article
Duffus, D., Rodl, V., Sands, B. et al. Enumeration of order preserving maps. Order 9, 15–29 (1992). https://doi.org/10.1007/BF00419036
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00419036