|Ph. D.: IM PAN 1973, habilitation: IM PAN 1985|
My areas of research are measure theory, functional analysis and operator theory. I am also interested in the history of 20th century mathematics. I am mainly concerned with extending additive functions on algebras of sets and operators on vector lattices, and with constructions and properties of dense subspaces [resp. sublattices] of topological vector spaces [resp. lattices]. Some of my results on these subjects are included in several books and monographs (e.g., C. D. Aliprantis and O. Burkinshaw, Positive Operators, Academic Press, 1985; P. Pérez Carreras and J. Bonet, Barrelled Locally Convex Spaces, North-Holland, 1987).
Part of my work is devoted to the variation and semivariations of an additive function defined on a Boolean algebra and taking values in a Banach space or an Abelian normed group.
I participated in the editorial work of Colloquium Mathematicum (1973-74). I was engaged in the publication of W. Sierpiński's Oeuvres choisies (1974-76) and Selected Papers of Antoni Zygmund (1989). I was one of the editors of E. Marczewski's Collected Mathematical Papers (1996).
Referee for many Polish and foreign mathematical journals, reviewer for Mathematical Reviews (1976--2004) and Zentralblatt für Mathematik (1981--2016).