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Journal of Convex Analysis 30 (2023), No. 1, 065--080 Copyright Heldermann Verlag 2023 On Special Partitions of [0,1] and Lineability within Families of Bounded Variation Functions Luis Bernal-González Dep. de Análisis Matemático, Facultad de Matemáticas, Inst. de Matemáticas Antonio de Castro Brzezicki, Universidad de Sevilla, Spain lbernal@us.es Juan Fernández-Sánchez Universidad de Almería, Spain juanfernandez@ual.es Juan B. Seoane-Sepulveda Inst. de Matemática Interdisciplinar, Dep. de Análisis Matemático y Matemática Aplicada, Facultad de Ciencias Matemáticas, Universidad Complutense de Madrid, Spain jseoane@ucm.es Wolfgang Trutschnig Dept. of Mathematics, University of Salzburg, Austria wolfgang@trutschnig.net We show that there exist large algebraic structures (vector spaces, algebras, closed subspaces, etc.) formed entirely (except for 0), on one hand, by singular, nowhere monotonic functions on [0,1] and, on the other hand, by absolutely continuous nowhere monotonic functions. Several tools, of independent interest, related to obtaining special partitions of R into uncountable collections will be provided and used. The results obtained in this note are either new or improved versions of already existing ones. Keywords: Lineability, spaceability, bounded variation function, singular function, absolutely continuous function, nowhere monotonic function. MSC: 15A03, 46B87, 26A45, 26B30. [ Fulltext-pdf (162 KB)] for subscribers only. |