ABSTRACT
This chapter introduces the notion of a real-valued generalized step-function and investigate generalized step-functions in connection with the problem of sup-measurability of certain functions of two variables, regarded as superposition operators. It considers the question of measurability of functions obtained by using the superposition operator which is induced by a given function of two variables. In this connection, the chapter discusses some related measurability properties of functions of two variables. It also includes exercise problems related to the generalized step-functions and superposition operators.
