Spectral synthesis in the sobolev space generated by an integral metric

Let l ∈ ℕ, A ⊂ ℝⁿ . The main goal of this paper is to describe (in inner terms) the closure of the set {f ∈ W ₁ ^l : f=0 in a neighborhood of the set A} with respect to the norm of the space W ₁ ^l (ℝⁿ). Bibliography: 9 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 217, 1994, pp. 92–111.