Cobos, FernandoFernández-Cabrera, Luz M.Martínez, Antón2023-06-202023-06-2020050039-322310.4064/sm166-3-1https://hdl.handle.net/20.500.14352/50770The paper establishes necessary and sufficient conditions for compactness of operators acting between general K -spaces, general J -spaces and operators acting from a J -space into a K -space. Applications to interpolation of compact operators are also given.engjournal articlehttp://journals.impan.gov.pl/sm/Inf/166-3-1.htmlopen access519.6Análisis numérico1206 Análisis Numérico