Ein optimaler Satz über offene Abbildungen.
In this paper we develop a duality theory of the closed graph theorem with weak continuity conditions, in order to obtain some permanence and maximality properties concerning the domain and range classes.
We prove that entire and periodic cyclic cohomology satisfy excision for extensions of bornological algebras with a bounded linear section. That is, for such an extension we obtain a six term exact sequence in cohomology.