ABSTRACT
In this chapter, we consider a few related methods which analysts adopt when they
find that a problem is too challenging in its natural domain of variables. The basic
idea is to transform the problem into another domain, another view, where the prob-
lem structure is more transparent. The transform is useful if the desired results-
preferably exact, and sometimes only approximate or asymptotic-can then be ob-
tained in the original domain by an inverse transform.
