We investigate minimal pairs of continuous selections of four linear functions in three dimemsional space. Our purpose is to find minimal pairs of compact convex sets (polytopes) which represent all 166 continuous selections [see S. G. Bartels, L. Kuntz and S. Scholtes, Nonlinear Analysis, Theory, Meth. Appl. 24 (1995) 385-407] which can be made from the three coordinate functions and its negative sum. We find that these 166 selections are represented by 16 essentialy different minimal pairs which were studied in previous papers of the authors [see J. Grzybowski, Arch. Math. 63 (1994) 173-181, and D. Pallaschke, S. Scholtes, R. Urbanski, Bull. Polish. Acad. Sci. Math. 39 (1991) 105-109]. Three out of 16 cases are minimal pairs that are not unique minimal representations in their own quotient classes. One of these quotient classes was already studied in the above mentioned paper of J. Grzybowski and in the papers of D. Pallaschke, R. Urbanski, Z. Oper. Res. 37 (1993) 129-150, and M. Wiernowolski, Studia Math. 124 (2) (1997) 149-154.

Contact details are reproduced from the original publication and may be historical.

J. Grzybowski

Faculty of Mathematics and Computer Science, Adam Mickiewicz University, Matejki 48/49,
60769 Poznań, Poland

Diethard Pallaschke

Institut f. Statistik und Wirtschaftstheorie, Universität Karlsruhe, Kaiserstr. 12,
76128 Karlsruhe, Germany

R. Urbański

Faculty of Mathematics and Computer Science, Adam Mickiewicz University, Matejki 48/49,
60769 Poznań, Poland

  1. A. A. Agrachev, D. Pallaschke, S. Scholtes: On Morse theory for piecewise smooth functions, Journal of Dynamical and Control Systems 3 (1997) 449–469.https://doi.org/10.1023/A:1021810206861Google Scholar
  2. S. G. Bartels, L. Kuntz, S. Scholtes: Continuous selections of linear functions and nonsmooth critical point theory, Nonlinear Analysis, Theory, Meth. & Appl. 24 (1995) 385–407.https://doi.org/10.1016/0362-546X(95)91645-6Google Scholar
  3. V. F. Dem’yanov: Quasidifferential Calculus, New York, 1986.https://doi.org/10.1007/BFb0121132Google Scholar
  4. G. Ewald: Combinatorial Convexity and Algebraic Geometry, Springer-Verlag, Berlin et al., 1996.https://doi.org/10.1007/978-1-4612-4044-0Google Scholar
  5. J. Grzybowski: Minimal pairs of convex compact sets, Arch. Math. 63 (1994) 173–181.https://doi.org/10.1007/BF01189892Google Scholar
  6. L. Hörmander: Sur la fonction d’appui des ensembles convexes dans un espace localement convexe, Arkiv för Matematik 3 (1955) 181–186.https://doi.org/10.1007/BF02589354Google Scholar
  7. H. Th. Jongen, P. Jonker, F. Twilt: Nonlinear Optimization in Rn, I. Morse Theory, Chebyshev Approximation, Peter Lang Verlag, Frankfurt et al., 1983.Google Scholar
  8. H. Th. Jongen, D. Pallaschke: On linearization and continuous selections of functions, Optimization 19 (1998) 343–353.https://doi.org/10.1080/02331938808843350Google Scholar
  9. D. Pallaschke, S. Scholtes, R. Urbański: On minimal pairs of convex compact sets, Bull. Polish. Acad. Sci. Math. 39 (1991) 105–109.Google Scholar
  10. D. Pallaschke, R. Urbański: Some criteria for the minimality of pairs of compact convex sets, Zeitschrift für Operations Research 37 (1993) 129–150.https://doi.org/10.1007/BF01414153Google Scholar
  11. D. Pallaschke, R. Urbański: A continuum of minimal pairs of compact convex sets which are not connected by translation, Journal of Convex Analysis 1 (1996) 83–95.https://doi.org/10.68381/jca03007Google Scholar
  12. A. G. Pinsker: The space of convex sets of a locally convex space, Trudy Leningrad Engineering-Economic Institute, 63 (1966) 13–17.Google Scholar
  13. H. Steinhaus: Kalejdoskop Matematyczny, Warszawa, 1989.Google Scholar
  14. R. Urbański: A generalization of the Minkowski-Rådström-Hörmander Theorem, Bull. Acad. Polon. Sér. Sci. Math. 24 (1976) 709–715.Google Scholar
  15. M. Wiernowolski: Minimality in asymmetry classes, Studia Math. 124(2) (1997) 149–154.https://doi.org/10.4064/sm-124-2-149-154Google Scholar

J. Grzybowski, D. Pallaschke, R. Urbański. “Minimal Pairs Representing Selections of Four Linear Functions in ℝ^3.” Journal of Convex Analysis 7 (2000), No. 2, 445–452. https://doi.org/10.68381/jca07024