KnowraHahn–Banach theoremLinked fromLinked fromThe 13 pages that link to Hahn–Banach theorem, each with the reason it gives.All 13Broader topic 2Related 8Compared with 3Stefan BanachBroader topic: It supplies a foundational extension principle in the functional analysis Banach helped build.Existence theoremBroader topic: It guarantees the existence of extensions that support results throughout functional analysis.