“…In the case of a homogeneous 2D defect which does not possess complex internal structure and intrinsic dynamical degrees of freedom, these boundary conditions can be reduced in the simplest case to the continuity of the elastic displacements u i and to the discontinuity of surface-projected bulk stresses σ zi , i = 1, 2, 3 (for more general boundary conditions which account for the discontinuity both of surface-projected bulk stresses and elastic displacements, see Refs. [5,15]). For the problem under consideration, the following boundary conditions will be used: u (1) x − u (2) x = 0, u (1) z − u (2) z = 0, ( 5)…”