The Non-Existence of Algorithm Deciding Whether a Constructive Compact Topological Space is Simply Connected

Authors

  • Jiahao Chen
  • Zheng Li
  • Zirui Li
  • Sihan Shen
  • Guangzhi Sun

DOI:

https://doi.org/10.61173/v524km74

Keywords:

constructive mathematics, topology, funda-mental group, algorithm

Abstract

This paper discusses the non-existence of an algorithm Q always deciding whether a constructive compact topological space is simply connected or not, that is whether its fundamental group is trivial or not. We construct a program R that generates compact topological spaces, then we use R and Q to get an extension of an unextendible function to get the contradiction and finish the proof.

References

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[2] A. M. Turing: Corrections, Proc. Lond. Math. Soc., ser. 2, 43 (1937).

[3] A. A. Markov: On constructive functions (in Russian) Trudy Mat. Inst. Steklov 52 (1958). English translation in Amer. Math. Soc. Transl. 2, 29 (1963)

[4] A. A. Markov: On constructive mathematics (in Russian) Trudy Mat. Inst. Steklov 67 (1962). English translation in Amer. Math. Soc. Transl. 2, 98 (1971)

[5] B. A. Kushner: Lectures on Constructive Mathematical Analysis. American Mathematical Society, Providence, Rhode Island.

[6] E. Bishop, D. Bridges: Constructive analysis. Springer- Verlag, Berlin (1985).

[7] J. R. Munkres: Topology.2nd edition. Prentice Hall.

[8] A. Shen, N.K. Vereshchagin: Computable Functions. American Mathematical Society.

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Published

2025-07-06