Using a convenient subbase on the second hyperspace of a compactum with the Vietoris topology, we prove that the mapping that takes each closed non-empty subset AA of an II-convex compactum XX to its closed idempotent convex hull is continuous. This implies that each neighborhood of the diagonal ΔXX×X\Delta_X\subset X\times X contains an idempotent convex neighborhood. The main result is the theorem that the topology on an idempotent convex compactum XX is determined by a family of idempotent convex pseudometrics (with one idempotent convex metric if XX is metrizable).

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Oleh Nykyforchyn

Institute of Mathematics, Casimir the Great University, Bydgoszcz, Poland
and: Dept. of Mathematics and Computer Science, V. Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine

oleh.nyk@gmail.com

Mariia Savchyn

Dept. of Mathematics and Computer Science, V. Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine

savchyn.mar@gmail.com

O. Nykyforchyn, M. Savchyn. “Metrization of Idempotent Convex Compacta.” Journal of Convex Analysis 29 (2022), No. 3, 717–730.