Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T18:58:19.592Z Has data issue: false hasContentIssue false

The fan theorem and unique existence of maxima

Published online by Cambridge University Press:  12 March 2014

Josef Berger
Affiliation:
Mathematisches Institut der Universität München, Theresienstr. 39, 80333 München, Germany. E-mail: josef.berger@mathematik.uni-muenchen.de
Douglas Bridges
Affiliation:
Department of Mathematics & Statistics, The University of Canterbury, Private Bag 4800, Christchurch, New Zealand. E-mail: D.Bridges@math.canterbury.ac.nz
Peter Schuster
Affiliation:
Mathematisches Institut der Universität Münchenm, Theresienstr. 39, 80333 München, Germany. E-mail: peter.schuster@mathematik.uni-muenchen.de

Abstract

The existence and uniqueness of a maximum point for a continuous real–valued function on a metric space are investigated constructively. In particular, it is shown, in the spirit of reverse mathematics, that a natural unique existence theorem is equivalent to the fan theorem.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2006

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]Aczel, P. and Rathjen, M., Notes on constructive set theory. Technical Report 40. Institut Mittag–Leffler. Royal Swedish Academy of Sciences. 2001.Google Scholar
[2]Bishop, E. and Bridges, D., Constructive analysis. Grundlehren der Matheraatischen Wissenschaften. vol. 279. Springer–Verlag, Heidelberg, 1985.CrossRefGoogle Scholar
[3]Bridges, D., A constructive proximinality property of finite–dimensional linear spaces. Rocky Mountain Journal of Mathematics, vol. 11 (1981), no. 4, pp. 491497.CrossRefGoogle Scholar
[4]Bridges, D., Recent progress in constructive approximation theory, The L.E.J. Brouwer Centenary Symposium (Troelstra, A.S. and van Dalen, D., editors). North–Holland, Amsterdam, 1982, pp. 4150.Google Scholar
[5]Bridges, D., Constructing local optima on a compact interval, preprint, Universität München, 2003.Google Scholar
[6]Bridges, D., Continuity and Lipschitz constants for continuous projections, preprint, University of Canterbury and Universität München, 2003.Google Scholar
[7]Bridges, D. and Richman, F., Varieties of constructive mathematics, London Mathematical Society Lecture Notes, vol. 97, Cambridge University Press, 1987.CrossRefGoogle Scholar
[8]Dummett, M., Elements of intuitionism, 2nd ed., Oxford Logic Guides, vol. 39, Clarendon Press, Oxford, 2000.CrossRefGoogle Scholar
[9]Ishihara, H.. Informal constructive reverse mathematics, Sūurikaisekikenkyūsho Kīkyūroko. vol. 1381 (2004), pp. 108117.Google Scholar
[10]Ko, K-I. Complexity theory of real functions, Birkhäuser, Boston–Basel–Berlin. 1991.CrossRefGoogle Scholar
[11]Kohlenbach, U., Effective moduli from ineffective uniqueness proofs. An unwinding of de La Vallée Poussin's proof for Chebycheff approximation, Annals of Pure and Applied Logic, vol. 64 (1993), pp. 2794.CrossRefGoogle Scholar
[12]Specker, E., Nicht konstruktiv beweisbare Sätze der Analysis, this Journal, vol. 14 (1949). pp. 145158.Google Scholar
[13]Weihrauch, K., Computable analysis, Springer–Verlag, Heidelberg, 2000.CrossRefGoogle Scholar