ABSTRACT
The role of mathematics became apparent with the development of quantum chemistry in works of L. Pauling (1901-1994) and others [1], and more recently discrete mathematics has started to play a role in solving diverse chemical problems even though this is, by far, less apparent. One of the tasks of this book is to bring to the attention of a wider circle of chemists the denite role that discrete mathematics plays in chemistry. In contrast to “traditional” mathematics, discrete mathematics is concerned with studies of properties of objects having discrete components, such as atoms in a molecule. It is therefore quite surprising that it took such a long time to recognize the relevance of discrete mathematics in chemistry, which facilitated the growth of mathematical chemistry [2-5]. The early indication to the importance of enumerations in structural chemistry, if we consider the enumeration of isomers in 1876 of Flawitsky [6] as a contribution to stereochemistry (which, of course, is a part of structural chemistry, too), was drawn by G. N. Lewis (1875-1946), who in 1923
wrote about his octet rule [7], a fundamental contribution to the understanding of the covalent bond, years before the emergence of quantum chemistry.
