Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-14T07:27:38.764Z Has data issue: false hasContentIssue false

On coherent families of finite-to-one functions

Published online by Cambridge University Press:  12 March 2014

Piotr Koszmider*
Affiliation:
Department of Mathematics, York University, North York, Ontario, Canada, M3J 1P3, E-mail: piotr@clid.yorku.ca

Abstract

We consider the existence of coherent families of finite-to-one functions on countable subsets of an uncountable cardinal κ. The existence of such families for κ implies the existence of a winning 2-tactic for player TWO in the countable-finite game on κ. We prove that coherent families exist on κ = ωn, where nω, and that they consistently exist for every cardinal κ. We also prove that iterations of Axiom A forcings with countable supports are Axiom A.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 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

[B]Baumgartner, J., Iterated forcing, Surveys in set theory (Mathias, A. R. D., editor), London Mathematical Society Lecture Note Series, vol. 87, Cambridge University Press, London and New York, 1983.Google Scholar
[J]Jensen, R. B., The fine structure of the constructable hierarchy, Annals of Mathematical Logic, vol. 4, 1972, pp. 229308.CrossRefGoogle Scholar
[Ju]Just, W., Iterations of axiom A forcing, notes, summer 1990.Google Scholar
[S]Scheepers, M., Concerning n-tactics in the countable-finite game, this Journal, vol. 56, no. 3(1991), pp. 786796.Google Scholar
[Ko]Koszmider, P., Uogólniene forsingu Sacksa z zastosowaniem w teorii algebr Boole'a, Master's thesis, University of Warsaw, 1987.Google Scholar
[K]Kunen, K., Set theory, North-Holland, Amsterdam, 1980.Google Scholar
[KV]Kunen, K. and Vaugham, J. E., Handbook of set-theoretic topology, North-Holland, Amsterdam, 1984.Google Scholar
[M]Miyamoto, T., Some results in forcing, Ph.D. thesis, Dartmouth, 1988.Google Scholar
[TI]Todorevic, S., Kurepa families and cofinal similarieties, notes, 12 1989.Google Scholar
[T2]Todorevic, S., Cofinal Kurepa families, seminar notes, 11 1990.Google Scholar