Removable singularities of solutions of second-order divergence-form elliptic equations

Let $L$ be a uniformly elliptic linear second-order differential operator in divergence form with bounded measurable coefficients in a bounded domain $G\subset\mathbb R^n$ $(n\geqslant2)$. In this paper, we introduce subclasses of the Sobolev class $W^{1,2}(G)_{\text{loc}}$ containing generalized solutions of the equation $Lu=0$ such that the closed sets of nonisolated removable singular points for such solutions can be described completely in terms of Hausdorff measures.