Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-19T01:24:45.972Z Has data issue: false hasContentIssue false

Combinatorial results for semigroups of order-preserving mappings

Published online by Cambridge University Press:  24 October 2008

Peter M. Higgins
Affiliation:
Department of Mathematics, University of Essex

Extract

Consider the finite set Xn = {1,2, …,n} ordered in the standard way. Let Tn denote the full transformation semigroup on Xn, that is, the semigroup of all mappings α: XnXn under composition. We shall call α order-preserving if ij implies iα ≤ jα for i,jXn, and α is decreasing if iα ≤ i for all iXn. This paper investigates combinatorial properties of the semigroup O of all order-preserving mappings on Xn, and of its subsemigroup C which consists of all decreasing and order-preserving mappings.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Feller, W.. An Introduction to Probability Theory and its Applications, 3rd edn. vol. 1 (Wiley, 1968).Google Scholar
[2]Garba, G. U.. Nilpotents in semigroups of partial one-to-one order-preserving mappings. Semigroup Forum 41 (1991), 115.Google Scholar
[3]Gomes, G. M. S. and Howie, J. M.. On the ranks of certain semigroups of order-preserving transformations. Semigroup Forum 40 (1990), 115.Google Scholar
[4]Harris, B.. A note on the number of idempotents in symmetric semigroups. J. Combin. Theory Ser. A 3 (1967), 12341235.Google Scholar
[5]Harris, B. and Schoenfeld, L.. The number of idempotent elements in symmetric semigroups. J. Combin. Theory Ser. A 3 (1967), 122135.Google Scholar
[6]Higgins, P. M.. The range order of a product of i transformations from a finite full transformation semigroup. Semigroup Forum 37 (1988), 3136.CrossRefGoogle Scholar
[7]Higgins, P. M.. Random products in semigroups of mappings. In Lattices, Semigroups and Universal Algebra (editors Almeida, J. et al.), (Plenum Press, 1990), pp. 89100.CrossRefGoogle Scholar
[8]Higgins, P. M.. Techniques of Semigroup Theory (Oxford University Press, 1992).CrossRefGoogle Scholar
[9]Higgins, P. M. and Williams, E. J.. Random functions on a finite set. Ars Combin. 26A (1988), 93102.Google Scholar
[10]Hilton, P. and Pedersen, J.. Catalan numbers, their generalization, and their uses. Math. Intelligencer 13 (1991), 6475.CrossRefGoogle Scholar
[11]Howie, J. M.. Products of idempotents in certain semigroups of transformations. Proc. Roy. Soc. Edinburgh Sect. A 17 (1971), 223236.Google Scholar
[12]Katz, L.. Probability of indecomposability of a random mapping function. Ann. Math. Statist. 26 (1955), 512517.CrossRefGoogle Scholar
[13]Kruskal, M. T.. The expected number of components under a random mapping function. Amer. Math. Monthly 61 (1954), 392397.CrossRefGoogle Scholar
[14]Pin, J. E.. Varieties of Formal Languages (Plenum Press, 1986).CrossRefGoogle Scholar