About correctnes of the diffraction problems in case of angle domains

The subject of the paper is the proof of correctnes of the problem of diffraction a plane wave by a wedge. (The problem is scalar, the wave numbers inside the wedge and outside it are different). The method of the proof is analogous of one in the book [2]. The most essential difference in the consideration of this paper and the book [2] connected with the “isomorfism theorem”.