Generalized second order differential operators and their lateral conditions
The differential operator (1.1) l aD + bD, a > O, d D ds defined on an interval s < s < s. may be reduced to the form (1.2) 92 aD, a > 0 by introducing a new variable x, namely, a solution of x 0. All solutions of this differential equation are monotonic, and x is determined up to a linear transformation. Putting