“…It was recently suggested [20,21,22,23,24] that, apart from those abovementioned interaction models, the ES status should also be attributed to less common ones, for which the real line of coordinates is splitted into subintervals wherein the potential admits different definitions, while being continuous on the whole line, and the wavefunctions remain piece-wise proportional to special functions, while being matched, as well as their first derivatives, at the subinterval limit points.…”