
Journal of Convex Analysis 26 (2019), No. 3, 823853 Copyright Heldermann Verlag 2019 On some Class of Polytopes in an Idempotent, Symmetrical and NonAssociative Convex Structure Walter Briec LAMPSLaboratory of Mathematics and Physics, University of Perpignan, 52 avenue Villeneuve, 66000 Perpignan, France briec@univperp.fr Bconvexity was defined by the author and C. D. Horvath [Bconvexity, Optimization 53(2) (2004) 103127] as a suitable PainlevéKuratowski limit of linear convexities. Recently, an alternative algebraic formulation over the whole Euclidean vector space was proposed by the author in further articles [Some remarks on an idempotent and nonassociative convex structure, J. Convex Analysis 22 (2015) 259289; and Separation properties in some idempotent and symmetrical convex structure, J. Convex Analysis 24 (2017) 11431168]. In this paper the structure of the polytopes arising in such a context is analyzed. It is first established that this notion of convexity has the interval and decompositions properties but fails the recursive property. Among the key results of the paper, it is proven that a polytope defined over R^{n} is the PainlevéKuratowski limit of a suitable sequence of generalized convex polytopes. Some analogues to the Helly, Radon and Caratheodory theorems are derived in the limit. A separation theorem for Bpolytopes is stated extending an earlier result recently established by the author [Separation properties in some idempotent and symmetrical convex structure, J. Convex Analysis 24 (2017) 11431168] for fixed Bconvex sets. Finally, considering the KuratowskiPainlevé limit of a suitable sequence of linear halfspaces the external representation of a Bpolytope is established over R^{n}. It follows that the interior of a Bpolytope defined over R^{n} satisfies the convexity criterion proposed by the author previously [Some remarks on an idempotent and nonassociative convex structure, J. Convex Analysis 22 (2015) 259289]. Keywords: Generalized mean, convexity, convex hull, duality, semilattice, Bconvexity. MSC: 06D50, 32F17. [ Fulltextpdf (270 KB)] for subscribers only. 