I. The topics of this book The concept of a matroid has been known for
more than five decades. Whitney (1935) introduced it as a common
generalization of graphs and matrices. In the last two decades, it has
become clear how important the concept is, for the following reasons:
(1) Combinatorics (or discrete mathematics) was considered by many to be
a collection of interesting, sometimes deep, but mostly unrelated ideas.
However, like other branches of mathematics, combinatorics also
encompasses some gen- eral tools that can be learned and then applied,
to various problems. Matroid theory is one of these tools. (2) Within
combinatorics, the relative importance of algorithms has in- creased
with the spread of computers. Classical analysis did not even consider
problems where "only" a finite number of cases were to be studied. Now
such problems are not only considered, but their complexity is often
analyzed in con- siderable detail. Some questions of this type (for
example, the determination of when the so called "greedy" algorithm is
optimal) cannot even be answered without matroidal tools.