It is not the object of the author to present comprehensive cov- erage
of any particular integral transformation or of any particular
development of generalized functions, for there are books available in
which this is done. Rather, this consists more of an introductory survey
in which various ideas are explored. The Laplace transforma- tion is
taken as the model type of an integral transformation and a number of
its properties are developed; later, the Fourier transfor- mation is
introduced. The operational calculus of Mikusinski is pre- sented as a
method of introducing generalized functions associated with the Laplace
transformation. The construction is analogous to the construction of the
rational numbers from the integers. Further on, generalized functions
associated with the problem of extension of the Fourier transformation
are introduced. This construction is anal- ogous to the construction of
the reals from the rationals by means of Cauchy sequences. A chapter
with sections on a variety of trans- formations is adjoined. Necessary
levels of sophistication start low in the first chapter, but they grow
considerably in some sections of later chapters. Background needs are
stated at the beginnings of each chapter. Many theorems are given
without proofs, which seems appro- priate for the goals in mind. A
selection of references is included. Without showing many of the details
of rigor it is hoped that a strong indication is given that a firm
mathematical foundation does actu- ally exist for such entities as the
"Dirac delta-function".