Article contents
Reverse mathematics and Ramsey's property for trees
Published online by Cambridge University Press: 12 March 2014
Abstract
We show, relative to the base theory RCA0: A nontrivial tree satisfies Ramsey's Theorem only if it is biembeddable with the complete binary tree. There is a class of partial orderings for which Ramsey's Theorem for pairs is equivalent to ACA0. Ramsey's Theorem for singletons for the complete binary tree is stronger than . hence stronger than Ramsey's Theorem for singletons for ω. These results lead to extensions of results, or answers to questions, of Chubb, Hirst, and McNicholl [3].
- Type
- Research Article
- Information
- Copyright
- Copyright © Association for Symbolic Logic 2010
References
REFERENCES
[1]Cholak, P., Jockusch, C., and Slaman, T., On the strength of Ramsey's theorem for pairs, this Journal, vol. 66 (2001), no. 1, pp. 1–55.Google Scholar
[2]Chong, C. T. and Yang, Y., Σ2 induction and infinite injury priority argument, I. Maximal sets and the jump operator, this Journal, vol. 63 (1998), no. 3, pp. 797–814.Google Scholar
[3]Chubb, J., Hirst, J., and McNicholl, T., Reverse mathematics, computability, and partitions of trees, this Journal, vol. 74 (2009), no. 1, pp. 201–215.Google Scholar
[4]Hirst, J., Combinatorics in subsystems of second order arithmetic, Ph.D. thesis, The Pennsylvania State University, 1987.Google Scholar
[6]Simpson, S., Subsystems of second order arithmetic, Perspectives in Mathematical Logic, Springer-Verlag, Berlin, 1999.CrossRefGoogle Scholar
- 9
- Cited by