Abstract
The strong continuity principle reads “every pointwise continuous function from a complete separable metric space to a metric space is uniformly continuous near each compact image.” We show that this principle is equivalent to the fan theorem for monotone \(\varPi ^{0}_{1}\) bars. We work in the context of constructive reverse mathematics.
Similar content being viewed by others
References
Aczel, P., Rathjen, M.: Notes on constructive set theory. Tech. Rep. 40, Institut Mittag-Leffler (2000/2001)
Berger, J.: The fan theorem and uniform continuity. In: Cooper, S.B., Löwe, B., Torenvliet, L. (eds.) New Computational Paradigms, CiE 2005. Lecture Notes in Computer Science, vol. 3526, pp. 18–22. Springer, Berlin (2005). https://doi.org/10.1007/11494645_3
Berger, J.: The logical strength of the uniform continuity theorem. In: Beckmann, A., Berger, U., Löwe, B., Tucker, J.V. (eds.) Logical Approaches to Computational Barriers, CiE 2006. Lecture Notes in Computer Science, vol. 3988, pp. 35–39. Springer, Berlin (2006). https://doi.org/10.1007/11780342_4
Berger, J.: A separation result for varieties of Brouwer’s fan theorem. In: Proceedings of the 10th Asian Logic Conference, pp. 85–92. World Scientific Publishing (2010). https://doi.org/10.1142/9789814293020_0003
Berger, J., Bridges, D.: A bizarre property equivalent to the \(\Pi ^0_1\)-fan theorem. Log. J. IGPL 14(6), 867–871 (2006). https://doi.org/10.1093/jigpal/jzl026
Bishop, E.: Foundations of Constructive Analysis. McGraw-Hill, New York (1967)
Bridges, D.: Constructive Functional Analysis. Research Notes in Mathematics, vol. 28. Pitman, London (1979)
Bridges, D., Vîţă, L.S.: Techniques of Constructive Analysis. Universitext. Springer, New York (2006). https://doi.org/10.1007/978-0-387-38147-3
Diener, H., Loeb, I.: Sequences of real functions on \([0,1]\) in constructive reverse mathematics. Ann. Pure Appl. Logic 157(1), 50–61 (2009). https://doi.org/10.1016/j.apal.2008.09.018
Ishihara, H.: Constructive reverse mathematics: compactness properties. In: Crosilla, L., Schuster, P. (eds.) From Sets and Types to Topology and Analysis: Towards Practicable Foundations for Constructive Mathematics, no. 48 in Oxford Logic Guides, pp. 245–267. Oxford University Press, Oxford (2005). https://doi.org/10.1093/acprof:oso/9780198566519.003.0016
Ishihara, H.: Reverse mathematics in Bishop’s constructive mathematics. Philos. Sci. Cah. Spéc. 6, 43–56 (2006). https://doi.org/10.4000/philosophiascientiae.406
Lubarsky, R.S., Diener, H.: Separating the fan theorem and its weakenings. In: Artemov, S., Nerode, A. (eds.) Logical Foundations of Computer Science, LFCS 2013. Lecture Notes in Computer Science, vol. 7734, pp. 280–295. Springer, Berlin, (2013). https://doi.org/10.1007/978-3-642-35722-0_20
Schuster, P.: What is continuity, constructively? J. UCS 11(12), 2076–2085 (2005). https://doi.org/10.3217/jucs-011-12-2076
Troelstra, A.S., van Dalen, D.: Constructivism in Mathematics: An Introduction. Volume I. Studies in Logic and the Foundations of Mathematics, vol. 121. North-Holland, Amsterdam (1988)
Troelstra, A.S., van Dalen, D.: Constructivism in Mathematics: An Introduction. Volume II. Studies in Logic and the Foundations of Mathematics, vol. 123. North-Holland, Amsterdam (1988)
Acknowledgements
I am grateful to Josef Berger and Makoto Fujiwara for useful discussions. I also thank Hajime Ishihara and Takako Nemoto for helpful comments. This work was carried out while the author was INdAM-COFUND-2012 fellow of Istituto Nazionale di Alta Matematica “F. Severi”(INdAM).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kawai, T. A continuity principle equivalent to the monotone \(\Pi ^{0}_{1}\) fan theorem. Arch. Math. Logic 58, 443–456 (2019). https://doi.org/10.1007/s00153-018-0644-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00153-018-0644-1
Keywords
- Constructive reverse mathematics
- Fan theorem
- Strongly continuous function
- Complete separable metric space