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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

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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