We establish conditions required for the existence and uniqueness of bounded solutions of the
Main Notation, Object of Investigation, and ResultsBy C 0 we denote a Banach space of functions x = x(t) continuous and bounded in R and taking values from R with normBy C 1 we denote a Banach space of functions x C ∈ 0 such that the derivative of each function is an element of the space C 0 with normFurther, by C we denote the set of all continuous functions y : R → R, M is the set of all strictly monotone functions g : R → R such that the set of values R g ( ) of each of these functions coincides with R, and F is the set of all continuous functions g : R → R such that, for each of these functions, R g ( ) = R and lim ( )An operator L : C 1 → C 0 is defined as follows:where x