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Convexity and unique minimum points

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Abstract

We show constructively that every quasi-convex, uniformly continuous function \(f:C \rightarrow \mathbb {R}\) with at most one minimum point has a minimum point, where C is a convex compact subset of a finite dimensional normed space. Applications include a result on strictly quasi-convex functions, a supporting hyperplane theorem, and a short proof of the constructive fundamental theorem of approximation theory.

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References

  1. Berger, J., Ishihara, H.: Brouwer’s fan theorem and unique existence in constructive analysis. Math. Log. Q. 51(4), 360–364 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  2. Berger, J., Bridges, D., Schuster, P.: The fan theorem and unique existence of maxima. J. Symb. Log. 71(2), 713–720 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  3. Berger, J., Svindland, G.: Convexity and constructive infima. Arch. Math. Log. 55, 873–881 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  4. Berger, J., Svindland, G.: A separating hyperplane theorem, the fundamental theorem of asset pricing, and Markov’s principle. Ann. Pure Appl. Log. 167, 1161–1170 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  5. Berger, J., Svindland, G.: Constructive convex programming. LMU Munich (2017) (Preprint)

  6. Bridges, D.S.: A constructive proximinality property of finite-dimensional linear subspaces. Rocky Mt. J. Math. 11(4), 491–497 (1981)

    Article  MathSciNet  MATH  Google Scholar 

  7. Bishop, E., Bridges, D.: Constructive Analysis. Springer, New York (1985)

    Book  MATH  Google Scholar 

  8. Bridges, D., Richman, F.: Varieties of Constructive Mathematics. London Math. Soc. Lecture Notes, vol. 97. Cambridge Univ. Press, Cambridge (1987)

    Book  MATH  Google Scholar 

  9. Bridges, D.S., Vîţă, L.S.: Techniques of Constructive Analysis. Universitext. Springer, New York (2006)

    MATH  Google Scholar 

  10. Julian, W., Richman, F.: A uniformly continuous function on \(\left[0,1\right]\) that is everywhere different from its infimum. Pac. J. Math. 111(2), 333–340 (1984)

    Article  MathSciNet  MATH  Google Scholar 

  11. Kohlenbach, U.: Effective moduli from ineffective uniqueness proofs. An unwinding of de La Vallée Poussin’s proof for Chebycheff approximation. Ann. Pure Appl. Log. 64, 27–94 (1993)

    Article  MATH  Google Scholar 

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Correspondence to Josef Berger.

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Berger, J., Svindland, G. Convexity and unique minimum points. Arch. Math. Logic 58, 27–34 (2019). https://doi.org/10.1007/s00153-018-0619-2

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  • DOI: https://doi.org/10.1007/s00153-018-0619-2

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