Real-variable functional theory is an important component of analysis, a subject that learns between analytic mathematics and functional analytics.We study measure theory, integral theory, bounded variational function theory in this book.First, we study the properties of measure spaces, measurable sets, and measurable functions.Then we study the integral of measurable functions in measure space, its properties, the relationship between the Riemann integral and the Lebesgue integral, and so on.Finally we study the addition of generalized measure concepts to bounded variational functions such...