Abstract
In this paper, we prove some theorems on fuzzy sets. We first show that, in order to demonstrate that the equality of shadows ofA andB implies the equality ofA andB, it is necessary to assume thatA andB are closed and thatS H (A)=S H (B) for any closed hyperplane hyperplaneH. We also obtain a separation theorem for two convex fuzzy sets in a Hilbert space. Finally, we investigate results relating to minimax theorems for fuzzy sets. We obtain a necessary and sufficient condition for compactness.
Similar content being viewed by others
References
Zadeh, L. A.,Fuzzy Sets, Information and Control, Vol. 8, pp. 338–353, 1965.
Von Neumann, J., Zür Theorie der Gesellshaftsspiele, Mathematische Annalen, Vol. 100, pp. 295–320, 1928.
Terkelsen, F.,Some Minimax Theorems, Mathematica Scandinavica, Vol. 31, pp. 405–413, 1972.
Takahashi, W.,Nonlinear Variational Inequalities and Fixed Point Theorems, Journal of the Mathematical Society of Japan, Vol. 28, pp. 168–181, 1976.
Zadeh, L. A.,Shadows of Fuzzy Sets, Problemy Peredachi Informatsii, Vol. 2, pp. 37–44, 1966.
Weiss, M. D.,Fixed Points, Separation, and Induced Topologies for Fuzzy Sets, Journal of Mathematical Analysis and Applications, Vol. 50, pp. 142–150, 1975.
Lowen, R.,Fuzzy Topological Spaces and Fuzzy Compactness, Journal of Mathematical Analysis and Applications, Vol. 56, pp. 621–633, 1976.
Nazaroff, G. J.,Fuzzy Topological Polysystems, Journal of Mathematical Analysis and Applications, Vol. 41, pp. 478–485, 1973.
Warren, R. H.,Optimality in Fuzzy Topological Polysystems, Journal of Mathematical Analysis and Applications, Vol. 54, pp. 309–315, 1976.
Dunford, N., andSchwartz, J. T.,Linear Operators, Part 1, John Wiley and Sons (Interscience Publishers), New York, New York, 1958.
Author information
Authors and Affiliations
Additional information
Communicated by G. Leitmann
The authors wish to express their sincere thanks to Professor Hisaharu Umegaki for his invaluable suggestions and advice.
Rights and permissions
About this article
Cite this article
Takahashi, M., Takahashi, W. Separation theorems and minimax theorems for fuzzy sets. J Optim Theory Appl 31, 177–194 (1980). https://doi.org/10.1007/BF00934109
Issue Date:
DOI: https://doi.org/10.1007/BF00934109