Hostname: page-component-f554764f5-rvxtl Total loading time: 0 Render date: 2025-04-21T10:54:09.880Z Has data issue: false hasContentIssue false

ON SOME OF BROUWER’S AXIOMS

Published online by Cambridge University Press:  16 April 2025

WIM VELDMAN*
Affiliation:
INSTITUTE FOR MATHEMATICS ASTROPHYSICS AND PARTICLE PHYSICS FACULTY OF SCIENCE RADBOUD UNIVERSITY POSTBUS 9010 6500 GL NIJMEGEN THE NETHERLANDS E-mail: [email protected]

Abstract

We argue that some of Brouwer’s assumptions, rejected by Bishop, should be considered and studied as possible axioms. We show that Brouwer’s Continuity Principle enables one to prove an intuitionistic Borel Hierarchy Theorem. We also explain that Brouwer’s Fan Theorem is useful for a development of the theory of measure and integral different from the one worked out by Bishop. We show that Brouwer’s bar theorem not only proves the Fan Theorem but also a stronger statement that we call the Almost-fan Theorem. The Almost-fan Theorem implies intuitionistic versions of Ramsey’s Theorem and the Bolzano-Weierstrass Theorem.

Type
Article
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of The Association for Symbolic Logic

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.)

Article purchase

Temporarily unavailable

Footnotes

Sadly, the author passed away on November 30, 2024.

References

Bishop, E. and Bridges, D., Constructive Analysis , Springer Verlag, Berlin, 1985.CrossRefGoogle Scholar
Borel, É., Sur quelques points de la théorie des fonctions . Annales Scientifiques de l’École Normale Supérieure , vol. 12 (1895), no. 3, pp. 955, also in [3, pp. 239-287].CrossRefGoogle Scholar
Borel, O. É., Tome 1 , Éditions du Centre National de Recherche Scientifique, Paris, 1972.Google Scholar
Bridges, D. and Richman, F., Varieties of Constructive Mathematics , Cambridge University Press, Cambridge, 1987.CrossRefGoogle Scholar
Bridges, D. S. and Vîţă, L. S., Techniques of Constructive Analysis , Springer, New York, 2006.Google Scholar
Bridges, D. S., Ishihara, H., Rathjen, M., and Schwichtenberg, H. (eds.), Handbook of Constructive Mathematics - Encyclopedia of Mathematics and Its Applications , 185, Cambridge University Press, Cambridge, 2023.Google Scholar
Brouwer, L. E. J., Begründung der Mengenlehre unabhängig vom Satz vom ausgeschlossenem Dritten. Erster Teil , Allgemeine Mengenlehre , (1918). KNAW Verhandelingen ${1}^e$ sectie 12 no. 5, also in [10, 150–190].Google Scholar
Brouwer, L. E. J., Über Definitionsbereiche von Funktionen . Mathematische Annalen , vol. 97 (1927), pp. 6075, also in [10], pp. 390–405.CrossRefGoogle Scholar
Brouwer, L. E. J., Points and spaces . Canadian Journal of Mathematics, vol. 6 (1954), pp. 117, also in [10], pp. 522–538.CrossRefGoogle Scholar
Brouwer, L. E. J., Collected Works, Vol. I: Philosophy and Foundations of Mathematics (Heyting, A., editor), North Holland, Amsterdam, 1975.Google Scholar
de Bruijn, N. G. and Erdös, P., A color problem for infinite graphs and a problem in the theory of relations . Proceedings of Koninklijke Nederlandse Akademie Wetenschappen, vol. 54 (1951), pp. 371373.Google Scholar
Coquand, T., A Note on the open induction principle, 1997. Available at www.cse.chalmers.se/coquand/open.ps Google Scholar
Dedekind, R., Stetigkeit und Irrationalzahlen , technische Hochschule Braunschweig, Braunschweig, 1872.Google Scholar
Driessen, B., Intuitionistic Probability Theory, Master Thesis in Mathematics , Radboud University, Nijmegen, 2018.Google Scholar
Graham, R. L., Rothschild, B. L. and Spencer, J. H., Ramsey Theory , second ed., Wiley, New York, 1990.Google Scholar
Heyting, A., Intuitionism, an Introduction , North Holland, Amsterdam, 1956.Google Scholar
Howard, W. A. and Kreisel, G., Transfinite induction and bar induction of types zero and one, and the role of continuity in intuitionistic analysis . Journal of Symbolic Logic , vol. 31 (1966), pp. 325358.CrossRefGoogle Scholar
Kleene, S. C., Recursive functions and intuitionistic mathematics , Proceedings of the International Congress of Mathematicians (Cambridge, MA, USA, August 30–September 6, 1950), 1952, vol. I, pp. 679685.Google Scholar
Kleene, S. C. and Vesley, R. E., The Foundations of Intuitionistic Mathematics, Especially in Relation to Recursive Functions , North-Holland, Amsterdam, 1965.Google Scholar
Paris, J. and Harrington, L., A mathematical incompleteness in Peano arithmetic , Handbook of Mathematical Logic (Barwise, J., editor), Studies in Logic and the Foundations of Mathematics, vol. 90, North Holland, Amsterdam, 1977, pp. 11331142.CrossRefGoogle Scholar
Ramsey, F. P., On a problem in formal logic . Proceedings of the London Mathematical Society , vol. 30 (1928), pp. 264286.Google Scholar
Rootselaar, B., Generalization of the Brouwer Integral , Thesis, Amsterdam, 1954.Google Scholar
Simpson, S.G., Subsystems of Second Order Arithmetic, Perspectives in Mathematical Logic , Springer Verlag, Berlin, 1999.CrossRefGoogle Scholar
Troelstra, A.S. and Dalen, D., Constructivism in Mathematics, an Introduction , Vols. I and II, North-Holland, Amsterdam, 1988.Google Scholar
Veldman, W., Investigations in Intuitionistic Hierarchy Theory , Ph.D. thesis, Katholieke Universiteit, Nijmegen, 1981.Google Scholar
Veldman, W., On the continuity of functions in intuitionistic real analysis, some remarks on Brouwer’s paper: ‘Über Definitionsbereiche von Funktionen’, Report 8210, Mathematisch Instituut, Katholieke Universiteit, Nijmegen, 1982.Google Scholar
Veldman, W., Some intuitionistic variations on the notion of a finite set of natural numbers, Perspectives on Negation, Essays in Honour of Johsan Js. de Iongh on the occasion of his 80th birthday (de Swart, H. C. M. and Bergmans, L. J. M., editors) Tilburg University Press, Tilburg, 1995, pp. 177202.Google Scholar
Veldman, W., On sets enclosed between a set and its double complement , Logic and Foundations of Mathematics (Cantini, A., editor), Proceedings Xth International Congress on Logic, Methodology and Philosophy of Science, Florence 1995, Vol. III , Kluwer Academic, Dordrecht, 1999, pp. 143154.CrossRefGoogle Scholar
Veldman, W., Understanding and using Brouwer’s Continuity Principle , Reuniting the Antipodes, constructive and nonstandard views of the continuum (Berger, U., Osswald, H., and Schuster, P., editors), Proceedings of a Symposium held in San Servolo/Venice, 1999 , Kluwer, Dordrecht, 2001, pp. 285302.CrossRefGoogle Scholar
Veldman, W., Bijna de waaierstelling . (Almost the Fan Theorem), Nieuw Archief voor Wiskunde, vijfde serie , vol. 2 (2001), pp. 330339.Google Scholar
Veldman, W., Two simple sets that are not positively Borel . Annals of Pure and Applied Logic , vol. 135 (2005), pp. 151209.CrossRefGoogle Scholar
Veldman, W., Brouwer’s real thesis on bars , Constructivism: Mathematics (Heinzmann, G. and Ronzitti, G., editors) Logic, Philosophy and Linguistics, Philosophia Scientiae, Cahier Spécial 6, Université Nancy 2, Nancy, 2006, pp. 2139.CrossRefGoogle Scholar
Veldman, W., The Borel hierarchy theorem from Brouwer’s intuitionistic perspective . The Journal of Symbolic Logic , vol. 73 (2008), pp. 164.CrossRefGoogle Scholar
Veldman, W., Some applications of Brouwer’s thesis on Bars , One Hundred Years of Intuitionism (1907–2007), The Cerisy Conference (van Atten, M., Boldini, P., Bourdeau, M., and Heinzmann, G., editors), Birkhäuser, Basel, 2008, pp. 326340.CrossRefGoogle Scholar
Veldman, W., The fine structure of the intuitionistic Borel hierarchy . The Review of Symbolic Logic , vol. 2 (2009), pp. 30101.CrossRefGoogle Scholar
Veldman, W., Brouwer’s Fan Theorem as an axiom and as a contrast to Kleene’s Alternative . Archive for Mathematical Logic , vol. 53 (2014), pp. 621693.CrossRefGoogle Scholar
Veldman, W., The principle of open induction on $\left[0,1\right]$ and the approximate-Fan theorem . The Notre Dame Journal of Formal Logic , to appear, arXiv:1408.2493.Google Scholar
Veldman, W., Treading in Brouwer’s footsteps , Contemporary Logic and Computing (Rezuş, A., editor), Series: Landscapes in Logic, Vol. 1, College Publications, London, 2020, pp. 355396.Google Scholar
Veldman, W., Intuitionism: An inspiration? . Jahresbericht de Deutschen Mathematiker-Vereinigung , vol. 123 (2021), pp. 221284.CrossRefGoogle Scholar
Veldman, W., Projective sets, intuitionistically . Journal of Logic and Analysis , vol. 14 (2022), pp. 185.CrossRefGoogle Scholar
Veldman, W., The Fan theorem, its strong negation and the determinacy of games . Archive for Mathematical Logic , (2024). https://doi.org/10.1007/s00153-024-00930-9.Google Scholar
Veldman, W. and Bezem, M., Ramsey’s theorem and the pigeonhole principle in intuitionistic mathematics . Journal of the London Mathematical Society , vol. 47 (1993), pp. 193211.CrossRefGoogle Scholar
Waaldijk, F., On the foundations of constructive mathematics - especially in relation to the theory of continuous functions . Foundations of Science , vol. 10 (2005), pp. 249324.CrossRefGoogle Scholar