This volume is devoted to nonstandard methods of analysis based on applying nonstandard models of set theory. The present monograph is concerned with the main trends in this field, infinitesimal analysis and Boolean-valued analysis. Here, the methods that have been developed in the last twenty-five years are explained in detail, and are collected in bookform for the first time.

Special attention is paid to general principles and fundamentals of formalisms for infinitesimals as well as to the technique of descents and ascents in a Boolean-valued universe. The book also includes various novel applications of nonstandard methods to ordered algebraic systems, vector lattices, subdifferentials, convex programming etc. that were developed in recent years.