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On Free Semigroups and Ramsey Numbers

Published online by Cambridge University Press:  20 November 2018

Gerard Lallement*
Affiliation:
Pennsylvania State University, Pennsylvania16802
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Abstract

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If the length of a word w in a free semigroup F(X) satisfies , then for every partition of F(X) into k classes, w has n consecutive factors of length ≥p in the same class. As a consequence, the diagonal Ramsey numbers R(pn+1, p+1, k) have 1+pnk as lower bound.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1974

References

1. Chvatal, V., Hypergraphs and Ramseyian theorems, Proc. Amer. Math. Soc. 27, (1971), 434-440.Google Scholar
2. Clifford, A. H. and Preston, G. B., The algebraic theory of semigroups, Vol. II, 1967, Amer. Math. Soc, Providence, R.I. Google Scholar
3. Erdös, P., Some remarks on the theory of graphs, Bull. Amer. Math. Soc. 53, 1947, 292-294.Google Scholar
4. Frasnay, C., Quelques problèmes combinatoires concernant les ordres totaux et les relations monomorphes, Ann. Inst. Fourier, Grenoble, 15, 1965, 415-524.Google Scholar
5. Ginsburg, S., The mathematical theory of context-free languages, 1966, McGraw-Hill.Google Scholar
6. Giraud, G. R., Une généralisation des nomblres et de Vinégalité de Schur, C.R. Acad. Se. Paris, t. 266 (1968), 437-440.Google Scholar
7. Greenwood, R. E. and Gleason, A. M., Combinatorial relations and chromatic graphs, Can. Journ. Math., 7, 1955, 1-7.Google Scholar
8. Hell, P., Ramsey Numbers, M.Sc. thesis, McMaster University, 1969.Google Scholar
9. Justin, J., Généralisation du théorème de Van der Waerden sur les semi-groupes répétitifs, J. Combinatorial Theory (A) 12, (1972), 357-367.Google Scholar
10. Ryser, H. J., Combinatorial mathematics, 1963, Cams Math. Monographs number 14.Google Scholar
11. Schützenberger, M. P., Quelques problèmes combinatoires de la théorie des automates, Cours de l’Institut de Programmation 1966–1967 rédigé par J. F. Perrot.Google Scholar