On Bianchi and Baecklund Transformations of Two-Dimensional Surfaces in E4

In this paper we discuss the existence and properties of the Bianchi transformations for pseudospherical surfaces in E4. The results of the paper show that the theory of Bianchi transformations in the discussed case is essentially different from the well-known case of pseudospherical surfaces in E3 (in general n-manifolds of constant and negative curvature in E2n-1)