%A Labovskiy Sergey M. %N 52 %D 2020 %L acta70936 %O Bibliogr.: 9. p. ; ĂśsszefoglalĂĄs angol nyelven %K DifferenciĂĄlegyenlet %T On discreteness of spectrum of a second order differential operator %X A new form of a necessary and sufficient conditions for the discreteness of the spectrum of singular operator â 1 Ď(x) (p(x)u 0 0 , ââ ⤠a ⤠x ⤠b ⤠+â is obtained. A simpler proof of the necessity is obtained.