Representation of essentially semi regular linear relations and perturbations

In the case of linear operator property P(B, k) was introduced by M.A. Kaashoek. this paper, we characterize essentially semi regular relation in terms k). After that and as an application result give some connection between relations. Further, will supplementary conditions on to be Fredholm. Then, analyze stability class relations under small perturbations Riesz operators. Finally, study properties spectrum a establish spectral mapping theorem.