Zy. Chen et Nn. Huang, COMPLETENESS OF THE JOST SOLUTIONS IN THE CASE OF THE NLS-CONDITION( EQUATION WITH NONVANISHING BOUNDARY), Acta physica Sinica, 3(5), 1994, pp. 321-327
In the case of the NLS+ equation with nonvanishing boundary condition,
a complete set of the Jost solutions is chosen, and its completeness
is shown by means of the Marchenko inverse scattering equation.