
Chapter 1
Introduction
In this chapter we introduce the main objects of study and describe their early history
as well as some later developments. In Section 1.1 the most classical of these objects –
set partitions – are introduced and first properties of the corresponding Stirling and Bell
numbers are discussed. Several further results are mentioned which will be discussed in later
chapters in detail (and from different angles). In Section 1.2 the early history of the formal
theory of operational or symbolical calculus is described and several results mentioned.
Furthermore, the connection to the physical theory of quantum mechanics is elucidated,
thereby ...