Solvability of the boundary value problem for some   differential--difference equations
  Solvability and smoothness of generalized solutions to boundary value problems for not self-adjoint differential-difference equations are studied. Necessary and sufficient conditions of Fredholmian solvability (with index zero) are established. Smoothness of generalized solutions is considered in terms of index of the corresponding differential--difference operator. 
Pavel Gurevich
math.CA